diff --git a/be/src/runtime/type_limit.h b/be/src/runtime/type_limit.h
index fcd44d5d3350392..d23a9f1921656c4 100644
--- a/be/src/runtime/type_limit.h
+++ b/be/src/runtime/type_limit.h
@@ -71,8 +71,8 @@ struct type_limit<vectorized::Decimal128> {
     }
     static vectorized::Decimal128 min() { return -max(); }
 };
-static Int256 MAX_DECIMAL256_INT({999999999999999999ll, 999999999999999999ll, 999999999999999999ll,
-                                  999999999999999999ll, 9999ll});
+static Int256 MAX_DECIMAL256_INT({18446744073709551615ul, 8607968719199866879ul,
+                                  532749306367912313ul, 1593091911132452277ul});
 template <>
 struct type_limit<vectorized::Decimal256> {
     static vectorized::Decimal256 max() { return vectorized::Decimal256(MAX_DECIMAL256_INT); }
diff --git a/be/src/vec/core/decimal_comparison.h b/be/src/vec/core/decimal_comparison.h
index 7ee6364c565f2f8..d7eb5cf9d19cb58 100644
--- a/be/src/vec/core/decimal_comparison.h
+++ b/be/src/vec/core/decimal_comparison.h
@@ -109,12 +109,16 @@ class DecimalComparison {
         }
 
         Shift shift;
-        if (scale_a < scale_b)
+        if (scale_a < scale_b) {
             shift.a = DataTypeDecimal<B>(max_decimal_precision<B>(), scale_b)
-                              .get_scale_multiplier(scale_b - scale_a);
-        if (scale_a > scale_b)
+                              .get_scale_multiplier(scale_b - scale_a)
+                              .value;
+        }
+        if (scale_a > scale_b) {
             shift.b = DataTypeDecimal<A>(max_decimal_precision<A>(), scale_a)
-                              .get_scale_multiplier(scale_a - scale_b);
+                              .get_scale_multiplier(scale_a - scale_b)
+                              .value;
+        }
 
         return apply_with_scale(a, b, shift);
     }
diff --git a/be/src/vec/core/types.h b/be/src/vec/core/types.h
index a0baae5b84b5e6c..1d7a597f6d493b1 100644
--- a/be/src/vec/core/types.h
+++ b/be/src/vec/core/types.h
@@ -415,7 +415,6 @@ struct Decimal {
             }
         }
 
-        // TODO: decimal256
         static constexpr auto precision =
                 std::is_same_v<T, Int32>
                         ? BeConsts::MAX_DECIMAL32_PRECISION
@@ -661,8 +660,11 @@ struct Decimal<Int256> {
         static constexpr auto precision =
                 std::is_same_v<T, Int32>
                         ? BeConsts::MAX_DECIMAL32_PRECISION
-                        : (std::is_same_v<T, Int64> ? BeConsts::MAX_DECIMAL64_PRECISION
-                                                    : BeConsts::MAX_DECIMAL128_PRECISION);
+                        : (std::is_same_v<T, Int64>
+                                   ? BeConsts::MAX_DECIMAL64_PRECISION
+                                   : (std::is_same_v<T, Int128>
+                                              ? BeConsts::MAX_DECIMAL128_PRECISION
+                                              : BeConsts::MAX_DECIMAL256_PRECISION));
         bool is_nagetive = value < 0;
         int max_result_length = precision + (scale > 0) // Add a space for decimal place
                                 + (scale == precision)  // Add a space for leading 0
@@ -684,7 +686,9 @@ struct Decimal<Int256> {
             frac_part = abs_value % decimal_scale_multiplier<T>(scale);
         }
         if constexpr (std::is_same_v<T, Int256>) {
-            std::string res {wide::to_string(whole_part)};
+            std::string dec_str {wide::to_string(whole_part)};
+            auto end = fmt::format_to(str.data() + pos, "{}", dec_str);
+            pos = end - str.data();
         } else {
             auto end = fmt::format_to(str.data() + pos, "{}", whole_part);
             pos = end - str.data();
@@ -713,6 +717,9 @@ struct Decimal<Int256> {
                                                     const T& scale_multiplier) const {
         if (UNLIKELY(value == std::numeric_limits<T>::min())) {
             if constexpr (std::is_same_v<T, Int256>) {
+                std::string dec_str {wide::to_string(value)};
+                auto end = fmt::format_to(dst, "{}", dec_str);
+                return end - dst;
             } else {
                 auto end = fmt::format_to(dst, "{}", value);
                 return end - dst;
@@ -735,6 +742,9 @@ struct Decimal<Int256> {
             frac_part = abs_value % scale_multiplier;
         }
         if constexpr (std::is_same_v<T, Int256>) {
+            std::string dec_str {wide::to_string(whole_part)};
+            auto end = fmt::format_to(dst + pos, "{}", dec_str);
+            pos = end - dst;
         } else {
             auto end = fmt::format_to(dst + pos, "{}", whole_part);
             pos = end - dst;
@@ -759,6 +769,9 @@ struct Decimal<Int256> {
             }
             if (frac_part) {
                 if constexpr (std::is_same_v<T, Int256>) {
+                    std::string dec_str {wide::to_string(frac_part)};
+                    auto end = fmt::format_to(dst + pos, "{}", dec_str);
+                    pos = end - dst;
                 } else {
                     auto end = fmt::format_to(&dst[pos], "{}", frac_part);
                     pos = end - dst;
diff --git a/be/src/vec/core/wide_integer.h b/be/src/vec/core/wide_integer.h
index 8492d67d96b21a6..c13e0092d47c72f 100644
--- a/be/src/vec/core/wide_integer.h
+++ b/be/src/vec/core/wide_integer.h
@@ -68,8 +68,8 @@ class integer {
     template <size_t Bits2, typename Signed2>
     constexpr integer<Bits, Signed>& operator=(const integer<Bits2, Signed2>& rhs) noexcept;
 
-    // template <typename Arithmetic>
-    // constexpr integer<Bits, Signed>& operator=(Arithmetic rhs) noexcept;
+    template <typename Arithmetic>
+    constexpr integer<Bits, Signed>& operator=(Arithmetic rhs) noexcept;
 
     template <typename Arithmetic>
     constexpr integer<Bits, Signed>& operator*=(const Arithmetic& rhs);
diff --git a/be/src/vec/core/wide_integer_impl.h b/be/src/vec/core/wide_integer_impl.h
index 381a5013ab29e8f..b3f1198d89ed50c 100644
--- a/be/src/vec/core/wide_integer_impl.h
+++ b/be/src/vec/core/wide_integer_impl.h
@@ -950,17 +950,17 @@ constexpr integer<Bits, Signed>& integer<Bits, Signed>::operator=(
     return *this;
 }
 
-// template <size_t Bits, typename Signed>
-// template <typename T>
-// constexpr integer<Bits, Signed>& integer<Bits, Signed>::operator=(T rhs) noexcept {
-//     if constexpr (IsTupleLike<T>::value)
-//         _impl::wide_integer_from_tuple_like(*this, rhs);
-//     else if constexpr (std::is_same_v<std::remove_cvref_t<T>, CityHash_v1_0_2::uint128>)
-//         _impl::wide_integer_from_cityhash_uint128(*this, rhs);
-//     else
-//         _impl::wide_integer_from_builtin(*this, rhs);
-//     return *this;
-// }
+template <size_t Bits, typename Signed>
+template <typename T>
+constexpr integer<Bits, Signed>& integer<Bits, Signed>::operator=(T rhs) noexcept {
+    if constexpr (IsTupleLike<T>::value)
+        _impl::wide_integer_from_tuple_like(*this, rhs);
+    else if constexpr (std::is_same_v<std::remove_cvref_t<T>, CityHash_v1_0_2::uint128>)
+        _impl::wide_integer_from_cityhash_uint128(*this, rhs);
+    else
+        _impl::wide_integer_from_builtin(*this, rhs);
+    return *this;
+}
 
 template <size_t Bits, typename Signed>
 template <typename T>
diff --git a/be/src/vec/data_types/data_type_decimal.h b/be/src/vec/data_types/data_type_decimal.h
index 8706cc28635725a..0034655886309f5 100644
--- a/be/src/vec/data_types/data_type_decimal.h
+++ b/be/src/vec/data_types/data_type_decimal.h
@@ -604,19 +604,6 @@ typename T::NativeType max_decimal_value(UInt32 precision) {
                                           (UInt32)(max_decimal_precision<T>() - precision));
 }
 
-/*
-mnt/disk2/tengjianping/doris-master/be/src/util/string_parser.hpp:699:43: error: no matching function for call to 'min_decimal_value'
-                    value = is_negative ? vectorized::min_decimal_value<vectorized::Decimal<T>>(
-                                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-/mnt/disk2/tengjianping/doris-master/be/src/vec/data_types/data_type_decimal.cpp:164:32: note: in instantiation of function template specialization 'doris::StringParser::string_to_decimal<doris::TYPE_DECIMAL256, wide::integer<256, int>>' requested here
-    res->value = StringParser::string_to_decimal<DataTypeDecimalSerDe<T>::get_primitive_type()>(
-                               ^
-/mnt/disk2/tengjianping/doris-master/be/src/vec/data_types/data_type_decimal.h:609:24: note: candidate template ignored: constraints not satisfied [with T = vectorized::Decimal<integer<256, int>>]
-typename T::NativeType min_decimal_value(UInt32 precision) {
-                       ^
-/mnt/disk2/tengjianping/doris-master/be/src/vec/data_types/data_type_decimal.h:608:14: note: because 'IsDecimalNumber<doris::vectorized::Decimal<wide::integer<256, int> > >' evaluated to false
-    requires IsDecimalNumber<T>
-*/
 template <typename T>
     requires IsDecimalNumber<T>
 typename T::NativeType min_decimal_value(UInt32 precision) {
diff --git a/be/test/vec/data_types/decimal_test.cpp b/be/test/vec/data_types/decimal_test.cpp
new file mode 100644
index 000000000000000..74a65dd2b246ad2
--- /dev/null
+++ b/be/test/vec/data_types/decimal_test.cpp
@@ -0,0 +1,81 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#include <gtest/gtest-message.h>
+#include <gtest/gtest-test-part.h>
+#include <gtest/gtest.h>
+
+#include <memory>
+
+#include "gtest/gtest_pred_impl.h"
+#include "runtime/type_limit.h"
+#include "vec/core/types.h"
+namespace doris::vectorized {
+
+TEST(DecimalTest, Decimal256) {
+    // 9999999999999999999999999999999999999999999999999999999999999999999999999999
+    Decimal256 dec1(type_limit<vectorized::Decimal256>::max());
+    auto des_str = dec1.to_string(10);
+    EXPECT_EQ(des_str,
+              "999999999999999999999999999999999999999999999999999999999999999999.9999999999");
+    des_str = dec1.to_string(0);
+    EXPECT_EQ(des_str,
+              "9999999999999999999999999999999999999999999999999999999999999999999999999999");
+    des_str = dec1.to_string(76);
+    EXPECT_EQ(des_str,
+              "0.9999999999999999999999999999999999999999999999999999999999999999999999999999");
+
+    auto dec2 = type_limit<vectorized::Decimal256>::min();
+    des_str = dec2.to_string(10);
+    EXPECT_EQ(des_str,
+              "-999999999999999999999999999999999999999999999999999999999999999999.9999999999");
+    des_str = dec2.to_string(0);
+    EXPECT_EQ(des_str,
+              "-9999999999999999999999999999999999999999999999999999999999999999999999999999");
+    des_str = dec2.to_string(76);
+    EXPECT_EQ(des_str,
+              "-0.9999999999999999999999999999999999999999999999999999999999999999999999999999");
+
+    // plus
+    Decimal256 dec3 = dec1 + dec2;
+    des_str = dec3.to_string(10);
+    EXPECT_EQ(des_str, "0.0000000000");
+    des_str = dec3.to_string(0);
+    EXPECT_EQ(des_str, "0");
+    des_str = dec3.to_string(76);
+    EXPECT_EQ(des_str,
+              "0.0000000000000000000000000000000000000000000000000000000000000000000000000000");
+
+    // minus
+    dec2 = type_limit<vectorized::Decimal256>::max();
+    dec3 = dec1 - dec2;
+    des_str = dec3.to_string(10);
+    EXPECT_EQ(des_str, "0.0000000000");
+
+    // multiply
+
+    // divide
+    dec1 = type_limit<vectorized::Decimal256>::max();
+    dec2 = vectorized::Decimal256(10);
+    dec3 = dec1 / dec2;
+    des_str = dec3.to_string(1);
+    EXPECT_EQ(des_str,
+              "99999999999999999999999999999999999999999999999999999999999999999999999999.9");
+
+    // overflow
+}
+} // namespace doris::vectorized
\ No newline at end of file