diff --git a/sot/opcode_translator/executor/opcode_executor.py b/sot/opcode_translator/executor/opcode_executor.py
index 45aeeec0b..6021b389d 100644
--- a/sot/opcode_translator/executor/opcode_executor.py
+++ b/sot/opcode_translator/executor/opcode_executor.py
@@ -924,6 +924,10 @@ def LOAD_DEREF(self, instr: Instruction):
             return
         namemap = self._code.co_cellvars + self._code.co_freevars
         name = namemap[instr.arg]
+        if isinstance(self._cells[name], NullVariable):
+            raise InnerError(
+                f"Deref variable '{name}' absent or have been deleted"
+            )
         self.stack.push(self._cells[name].cell_content())
 
     def COPY_FREE_VARS(self, instr: Instruction):
@@ -1005,6 +1009,15 @@ def STORE_DEREF(self, instr: Instruction):
         name = namemap[instr.arg]
         self._cells[name].set_value(self.stack.pop())
 
+    def DELETE_DEREF(self, instr: Instruction):
+        namemap = self._code.co_cellvars + self._code.co_freevars
+        name = namemap[instr.arg]
+        if isinstance(self._cells[name], NullVariable):
+            raise InnerError(
+                f"Deref variable '{name}' absent or have been deleted"
+            )
+        self._cells[name] = NullVariable()
+
     def STORE_FAST(self, instr: Instruction):
         """
         TODO: side effect may happen
diff --git a/tests/test_19_closure.py b/tests/test_19_closure.py
index e089030c3..781010a5a 100644
--- a/tests/test_19_closure.py
+++ b/tests/test_19_closure.py
@@ -1,9 +1,11 @@
 import inspect
+import types
 import unittest
 
 from test_case_base import TestCaseBase, strict_mode_guard
 
 import paddle
+from sot.psdb import check_no_breakgraph
 
 
 def foo(x: int, y: paddle.Tensor):
@@ -100,6 +102,17 @@ def load_1(a, b=5):
     return load_1(1)
 
 
+@check_no_breakgraph
+def closure_del():
+    x = 0
+
+    def load():
+        nonlocal x
+        del x
+
+    return load
+
+
 import numpy as np
 
 
@@ -142,7 +155,7 @@ def func7(a, b):
     return a + b
 
 
-def foo7():
+def test_builtin_decorator():
     return func7(3, 5)
 
 
@@ -155,26 +168,24 @@ def closure():
     return closure
 
 
-class TestExecutor(TestCaseBase):
-    def test_closure(self):
-        self.assert_results(foo, 1, paddle.to_tensor(2))
-        self.assert_results(foo2, paddle.to_tensor(2))
-        self.assert_results(foo3, paddle.to_tensor(2))
-        self.assert_results_with_global_check(
-            test_global, ["global_z"], paddle.to_tensor(2)
-        )
-        self.assert_results(foo5, paddle.to_tensor(2))
-        self.assert_results(foo6, paddle.to_tensor(2))
-        self.assert_results(numpy_sum, paddle.to_tensor(1))
-        with strict_mode_guard(0):
-            self.assert_results(
-                lambda_closure, paddle.to_tensor(2), paddle.to_tensor(1)
-            )
+def non_local_test(t: paddle.Tensor):
+    a = 1
 
+    def func1():
+        nonlocal a
+        t = a
+        a = 2
+        return t
 
-class TestExecutor2(TestCaseBase):
-    def test_closure(self):
-        self.assert_results(foo7)
+    def func2():
+        nonlocal a
+        a = 1
+        return a
+
+    t += func1()  # add 2
+    t += func2()  # add 1
+    t += a  # add 1
+    return t
 
 
 # Side Effect.
@@ -195,40 +206,56 @@ def test_slice_in_for_loop(x, iter_num=3):
     return out
 
 
-class TestExecutor3(TestCaseBase):
+class TestClosure(TestCaseBase):
     def test_closure(self):
-        tx = paddle.to_tensor([1.0, 2.0, 3.0])
-        # need side effect of list.
-        # self.assert_results(test_slice_in_for_loop, tx)
-
-
-def non_local_test(t: paddle.Tensor):
-    a = 1
+        self.assert_results(foo, 1, paddle.to_tensor(2))
+        self.assert_results(foo2, paddle.to_tensor(2))
+        self.assert_results(foo3, paddle.to_tensor(2))
+        self.assert_results(foo5, paddle.to_tensor(2))
 
-    def func1():
-        nonlocal a
-        t = a
-        a = 2
-        return t
+    def test_global(self):
+        self.assert_results_with_global_check(
+            test_global, ["global_z"], paddle.to_tensor(2)
+        )
 
-    def func2():
-        nonlocal a
-        a = 1
-        return a
+    def test_lambda(self):
+        with strict_mode_guard(0):
+            self.assert_results(
+                lambda_closure, paddle.to_tensor(2), paddle.to_tensor(1)
+            )
 
-    t += func1()  # add 2
-    t += func2()  # add 1
-    t += a  # add 1
-    return t
+    def test_numpy(self):
+        self.assert_results(numpy_sum, paddle.to_tensor(1))
 
+    def test_del_deref(self):
+        def is_empty_cell(cell: types.CellType):
+            try:
+                cell.cell_contents  # noqa: B018
+                return False
+            except ValueError as e:
+                if "Cell is empty" in str(e):
+                    return True
+                return False
+
+        closure_del_func = closure_del()
+        # Why is it 0: Only one value x is stored in the closure_del method __Closure__ in
+        self.assertFalse(is_empty_cell(closure_del_func.__closure__[0]))
+        closure_del_func()
+        self.assertTrue(is_empty_cell(closure_del_func.__closure__[0]))
+
+    def test_decorator(self):
+        self.assert_results(test_builtin_decorator)
+        self.assert_results(foo6, paddle.to_tensor(2))
 
-class TestExecutor4(TestCaseBase):
-    def test_closure(self):
+    def test_nolocal(self):
         tx = paddle.to_tensor([1.0])
         self.assert_results(non_local_test, tx)
 
+    def test_side_effect(self):
+        tx = paddle.to_tensor([1.0, 2.0, 3.0])
+        # need side effect of list.
+        self.assert_results_with_side_effects(test_slice_in_for_loop, tx)
 
-class TestCreateClosure(TestCaseBase):
     def test_create_closure(self):
         closure = create_closure()
         self.assert_results(closure)