diff --git a/source/source_io/read_input_item_relax.cpp b/source/source_io/read_input_item_relax.cpp
index 59c6ab187a..f8c3453893 100644
--- a/source/source_io/read_input_item_relax.cpp
+++ b/source/source_io/read_input_item_relax.cpp
@@ -31,8 +31,10 @@ void ReadInput::item_relax()
             ModuleBase::WARNING_QUIT("ReadInput", warningstr);
         }
         };
+        sync_stringvec(input.relax_method, para.input.relax_method.size(), "");
         this->add_item(item);
         
+        
         // Input_Item item("relax_method");
         // item.annotation = "cg; bfgs; sd; cg; cg_bfgs;";
         // read_sync_string(input.relax_method);