diff --git a/deepmd/dpmodel/atomic_model/polar_atomic_model.py b/deepmd/dpmodel/atomic_model/polar_atomic_model.py
index 6057c5ba65..bc7860491c 100644
--- a/deepmd/dpmodel/atomic_model/polar_atomic_model.py
+++ b/deepmd/dpmodel/atomic_model/polar_atomic_model.py
@@ -43,7 +43,6 @@ def apply_out_stat(
             dtype = out_bias[self.bias_keys[0]].dtype
             for kk in self.bias_keys:
                 ntypes = out_bias[kk].shape[0]
-                temp = xp.zeros(ntypes, dtype=dtype)
                 temp = xp.mean(
                     xp.diagonal(out_bias[kk].reshape(ntypes, 3, 3), axis1=1, axis2=2),
                     axis=1,