diff --git a/primitive_process/src/base/primitive.cpp b/primitive_process/src/base/primitive.cpp
index ef3078f..6d7c596 100644
--- a/primitive_process/src/base/primitive.cpp
+++ b/primitive_process/src/base/primitive.cpp
@@ -34,9 +34,9 @@ dynamic_bitset_mp<> primitive::judge_sign_by_subface_sign(stl_vector_mp<dynamic_
     dynamic_bitset_mp<> res = subface_signs.front();
     for (size_t i = 1; i < get_subface_count(); ++i) {
         if (!subfaces[i].is_marked())
-            res &= subface_signs[i];
+            res |= subface_signs[i];
         else
-            res &= subface_signs[i].flip();
+            res |= subface_signs[i].flip();
     }
 
     return res;