diff --git a/工具v4/批量收录新题.py b/工具v4/批量收录新题.py
index d249b8e0..fba6d90f 100644
--- a/工具v4/批量收录新题.py
+++ b/工具v4/批量收录新题.py
@@ -63,7 +63,7 @@ class MyWindow_bdsl(QWidget,Ui_Form):
                     psrstring = "rep"+id+","
                 elif simrate > 0.5:
                     psrstring += id + ","
-            if psrstring[-1] == ",":
+            if len(psrstring) > 0 and psrstring[-1] == ",":
                 psrstring = psrstring[:-1]
             if len(psrstring) > 0:
                 output += f"\\item [{psrstring}] {p}\n\n"