diff --git a/fe/fe-core/src/main/java/org/apache/doris/analysis/ColumnDef.java b/fe/fe-core/src/main/java/org/apache/doris/analysis/ColumnDef.java
index 93bcb92f58062a..c2c55c4ce7c955 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/analysis/ColumnDef.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/analysis/ColumnDef.java
@@ -134,7 +134,8 @@ public static DefaultValue currentTimeStampDefaultValueWithPrecision(Long precis
         }
 
         public boolean isCurrentTimeStamp() {
-            return "CURRENT_TIMESTAMP".equals(value) && NOW.equals(defaultValueExprDef.getExprName());
+            return "CURRENT_TIMESTAMP".equals(value) && defaultValueExprDef != null
+                    && NOW.equals(defaultValueExprDef.getExprName());
         }
 
         public boolean isCurrentTimeStampWithPrecision() {
diff --git a/regression-test/data/alter_p0/test_alter_add_column_default_value_str.out b/regression-test/data/alter_p0/test_alter_add_column_default_value_str.out
new file mode 100644
index 00000000000000..b180902fd16246
--- /dev/null
+++ b/regression-test/data/alter_p0/test_alter_add_column_default_value_str.out
@@ -0,0 +1,14 @@
+-- This file is automatically generated. You should know what you did if you want to edit this
+-- !select1 --
+1	1	1
+2	2	2
+3	3	3
+
+-- !select4 --
+1	1	1	CURRENT_TIMESTAMP	BITMAP_EMPTY
+2	2	2	CURRENT_TIMESTAMP	BITMAP_EMPTY
+3	3	3	CURRENT_TIMESTAMP	BITMAP_EMPTY
+4	4	4	4	4
+5	5	5	5	5
+6	6	6	6	6
+
diff --git a/regression-test/suites/alter_p0/test_alter_add_column_default_value_str.groovy b/regression-test/suites/alter_p0/test_alter_add_column_default_value_str.groovy
new file mode 100644
index 00000000000000..f3d0386498193b
--- /dev/null
+++ b/regression-test/suites/alter_p0/test_alter_add_column_default_value_str.groovy
@@ -0,0 +1,72 @@
+// 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.
+
+suite('test_alter_add_column_default_value_str') {
+    def tbl = 'test_alter_add_column_default_value_str_tbl'
+    sql "DROP TABLE IF EXISTS ${tbl} FORCE"
+    sql """
+        CREATE TABLE ${tbl} (
+            `k1` BIGINT NOT NULL,
+            `v1` BIGINT NULL,
+            `v2` INT NULL,
+        ) ENGINE=OLAP
+        UNIQUE KEY(`k1`)
+        DISTRIBUTED BY HASH(`k1`) BUCKETS 1
+        PROPERTIES (
+            "replication_allocation" = "tag.location.default: 1"
+        );
+    """
+
+    sql """
+        INSERT INTO ${tbl} VALUES (1,1,1),(2,2,2),(3,3,3)
+    """
+
+    sql """ SYNC """
+
+    // Check data before ALTER TABLE
+    qt_select1 """ SELECT * FROM ${tbl} ORDER BY k1 """
+    def tb1 = sql """ show create table ${tbl}"""
+    logger.info("tb1:{}", tb1[0][1])
+    assertFalse(tb1[0][1].contains("varchar(20) NOT NULL DEFAULT \"CURRENT_TIMESTAMP\""))
+    assertFalse(tb1[0][1].contains("varchar(20) NOT NULL DEFAULT \"BITMAP_EMPTY\""))
+
+    sql """
+        ALTER TABLE ${tbl} add column timestamp_default varchar(20) NOT NULL default "CURRENT_TIMESTAMP";
+    """
+
+    sql """
+        ALTER TABLE ${tbl} add column bitmap_default varchar(20) NOT NULL default "BITMAP_EMPTY";
+    """
+
+    waitForSchemaChangeDone {
+        sql """ SHOW ALTER TABLE COLUMN WHERE TableName='${tbl}' ORDER BY createtime DESC LIMIT 1 """
+        time 600
+    }
+
+    // Check table structure after ALTER TABLE
+    def tb2 = sql """ show create table ${tbl}"""
+    logger.info("tb2:{}", tb2[0][1])
+    assertTrue(tb2[0][1].contains("varchar(20) NOT NULL DEFAULT \"CURRENT_TIMESTAMP\""))
+    assertTrue(tb2[0][1].contains("varchar(20) NOT NULL DEFAULT \"BITMAP_EMPTY\""))
+    def resultCreate = sql """ SHOW CREATE TABLE ${tbl} """
+    sql """insert into ${tbl} values (4,4,4,"4","4")"""
+    sql """insert into ${tbl} (k1,v1,v2,timestamp_default,bitmap_default) values (5,5,5,5,"5")"""
+    sql """insert into ${tbl} (k1,v1,v2,timestamp_default,bitmap_default) values (6,6,6,6,"6")"""
+    qt_select4 """ SELECT k1,v1,v2,timestamp_default,bitmap_default FROM ${tbl} ORDER BY k1 """
+
+    sql "DROP TABLE IF EXISTS ${tbl} FORCE"
+}