diff --git a/crazy_functions/latex_fns/latex_toolbox.py b/crazy_functions/latex_fns/latex_toolbox.py
index a0c889a8..5adc7ea8 100644
--- a/crazy_functions/latex_fns/latex_toolbox.py
+++ b/crazy_functions/latex_fns/latex_toolbox.py
@@ -281,9 +281,12 @@ def rm_comments(main_file):
 def find_tex_file_ignore_case(fp):
     dir_name = os.path.dirname(fp)
     base_name = os.path.basename(fp)
+    # 如果输入的文件路径是正确的
+    if os.path.exists(pj(dir_name, base_name)): return pj(dir_name, base_name)
+    # 如果不正确，试着加上.tex后缀试试
     if not base_name.endswith('.tex'): base_name+='.tex'
     if os.path.exists(pj(dir_name, base_name)): return pj(dir_name, base_name)
-    # go case in-sensitive
+    # 如果还找不到，解除大小写限制，再试一次
     import glob
     for f in glob.glob(dir_name+'/*.tex'):
         base_name_s = os.path.basename(fp)