diff --git a/deepmd/utils/spin.py b/deepmd/utils/spin.py
index e1f40bc3b9..38e8da48da 100644
--- a/deepmd/utils/spin.py
+++ b/deepmd/utils/spin.py
@@ -57,9 +57,8 @@ def __init__(
             if len(virtual_scale) == self.ntypes_real:
                 self.virtual_scale = virtual_scale
             elif len(virtual_scale) == self.ntypes_spin:
-                self.virtual_scale = virtual_scale + [
-                    0.0 for _ in range(self.ntypes_real - self.ntypes_spin)
-                ]
+                self.virtual_scale = np.zeros(self.ntypes_real)
+                self.virtual_scale[self.use_spin] = virtual_scale
             else:
                 raise ValueError(
                     f"Invalid length of virtual_scale for spin atoms"
diff --git a/source/tests/common/test_spin.py b/source/tests/common/test_spin.py
new file mode 100644
index 0000000000..c3bca50b09
--- /dev/null
+++ b/source/tests/common/test_spin.py
@@ -0,0 +1,172 @@
+# SPDX-License-Identifier: LGPL-3.0-or-later
+import os
+import unittest
+
+import numpy as np
+
+from deepmd.utils.spin import (
+    Spin,
+)
+
+CUR_DIR = os.path.dirname(__file__)
+
+
+class SpinTest(unittest.TestCase):
+    def setUp(self):
+        type_map_1 = ["H", "O"]
+        self.use_spin_1 = [False, False]
+        self.virtual_scale_1 = [0.1, 0.1]
+
+        type_map_2 = ["B", "Ni", "O"]
+        self.use_spin_2 = [False, True, False]
+        self.virtual_scale_2 = [0.1, 0.1, 0.1]
+
+        type_map_3 = ["H", "O", "B", "Ni", "O"]
+        self.use_spin_3 = [False, False, False, True, False]
+        self.virtual_scale_3 = [0.1, 0.1, 0.1, 0.1, 0.1]
+
+        self.virtual_scale_float = 0.1
+        self.virtual_scale_nspin = [0.1]
+
+        self.spin_1 = Spin(self.use_spin_1, self.virtual_scale_1)
+        self.spin_2 = Spin(self.use_spin_2, self.virtual_scale_2)
+        self.spin_3 = Spin(self.use_spin_3, self.virtual_scale_3)
+        self.spin_3_float = Spin(self.use_spin_3, self.virtual_scale_float)
+        self.spin_3_nspin = Spin(self.use_spin_3, self.virtual_scale_nspin)
+
+        self.expect_virtual_scale_mask_1 = np.array([0.0, 0.0])
+        self.expect_virtual_scale_mask_2 = np.array([0.0, 0.1, 0.0])
+        self.expect_virtual_scale_mask_3 = np.array([0.0, 0.0, 0.0, 0.1, 0.0])
+
+        self.expect_pair_exclude_types_1 = [
+            [2, 0],
+            [2, 1],
+            [2, 2],
+            [2, 3],
+            [3, 0],
+            [3, 1],
+            [3, 2],
+            [3, 3],
+        ]
+        self.expect_pair_exclude_types_2 = [
+            [3, 0],
+            [3, 1],
+            [3, 2],
+            [3, 3],
+            [3, 4],
+            [3, 5],
+            [5, 0],
+            [5, 1],
+            [5, 2],
+            [5, 3],
+            [5, 4],
+            [5, 5],
+        ]
+        self.expect_pair_exclude_types_3 = [
+            [5, 0],
+            [5, 1],
+            [5, 2],
+            [5, 3],
+            [5, 4],
+            [5, 5],
+            [5, 6],
+            [5, 7],
+            [5, 8],
+            [5, 9],
+            [6, 0],
+            [6, 1],
+            [6, 2],
+            [6, 3],
+            [6, 4],
+            [6, 5],
+            [6, 6],
+            [6, 7],
+            [6, 8],
+            [6, 9],
+            [7, 0],
+            [7, 1],
+            [7, 2],
+            [7, 3],
+            [7, 4],
+            [7, 5],
+            [7, 6],
+            [7, 7],
+            [7, 8],
+            [7, 9],
+            [9, 0],
+            [9, 1],
+            [9, 2],
+            [9, 3],
+            [9, 4],
+            [9, 5],
+            [9, 6],
+            [9, 7],
+            [9, 8],
+            [9, 9],
+        ]
+
+    def test_ntypes(self):
+        self.assertEqual(self.spin_1.get_ntypes_real(), 2)
+        self.assertEqual(self.spin_1.get_ntypes_spin(), 0)
+        self.assertEqual(self.spin_1.get_ntypes_real_and_spin(), 2)
+        self.assertEqual(self.spin_1.get_ntypes_input(), 4)
+
+        self.assertEqual(self.spin_2.get_ntypes_real(), 3)
+        self.assertEqual(self.spin_2.get_ntypes_spin(), 1)
+        self.assertEqual(self.spin_2.get_ntypes_real_and_spin(), 4)
+        self.assertEqual(self.spin_2.get_ntypes_input(), 6)
+
+        self.assertEqual(self.spin_3.get_ntypes_real(), 5)
+        self.assertEqual(self.spin_3.get_ntypes_spin(), 1)
+        self.assertEqual(self.spin_3.get_ntypes_real_and_spin(), 6)
+        self.assertEqual(self.spin_3.get_ntypes_input(), 10)
+
+    def test_use_spin(self):
+        np.testing.assert_allclose(self.spin_1.get_use_spin(), self.use_spin_1)
+        np.testing.assert_allclose(self.spin_2.get_use_spin(), self.use_spin_2)
+        np.testing.assert_allclose(self.spin_3.get_use_spin(), self.use_spin_3)
+
+    def test_mask(self):
+        np.testing.assert_allclose(
+            self.spin_1.get_virtual_scale_mask(), self.expect_virtual_scale_mask_1
+        )
+        np.testing.assert_allclose(
+            self.spin_2.get_virtual_scale_mask(), self.expect_virtual_scale_mask_2
+        )
+        np.testing.assert_allclose(
+            self.spin_3.get_virtual_scale_mask(), self.expect_virtual_scale_mask_3
+        )
+
+    def test_exclude_types(self):
+        self.assertEqual(
+            sorted(self.spin_1.get_pair_exclude_types()),
+            sorted(self.expect_pair_exclude_types_1),
+        )
+        self.assertEqual(
+            sorted(self.spin_2.get_pair_exclude_types()),
+            sorted(self.expect_pair_exclude_types_2),
+        )
+        self.assertEqual(
+            sorted(self.spin_3.get_pair_exclude_types()),
+            sorted(self.expect_pair_exclude_types_3),
+        )
+
+    def test_virtual_scale_consistence(self):
+        np.testing.assert_allclose(
+            self.spin_3.get_virtual_scale(), self.spin_3_float.get_virtual_scale()
+        )
+        np.testing.assert_allclose(
+            self.spin_3.get_virtual_scale_mask(), self.spin_3_nspin.get_virtual_scale()
+        )
+        np.testing.assert_allclose(
+            self.spin_3.get_virtual_scale_mask(),
+            self.spin_3_float.get_virtual_scale_mask(),
+        )
+        np.testing.assert_allclose(
+            self.spin_3.get_virtual_scale_mask(),
+            self.spin_3_nspin.get_virtual_scale_mask(),
+        )
+        self.assertEqual(
+            self.spin_3.get_pair_exclude_types(),
+            self.spin_3_float.get_pair_exclude_types(),
+        )