diff --git a/src/modules/tpm/challengesnew/tpm-md-editor.js b/src/modules/tpm/challengesnew/tpm-md-editor.js
index a8243879..9d174a65 100644
--- a/src/modules/tpm/challengesnew/tpm-md-editor.js
+++ b/src/modules/tpm/challengesnew/tpm-md-editor.js
@@ -231,6 +231,7 @@ export default ({ mdID, onChange, onCMBeforeChange, onCMBlur, error = false, cla
             document.onkeydown = (e) => {
               if (e.key === "@") {
                 // 输入@键后在对应的位置显示可选的项目成员
+                const selection = window.getSelection().anchorOffset;
                 setAtWhoVisible(true);
               }else{
                 setAtWhoVisible(false);