diff --git a/app/Models/CourseSign.php b/app/Models/CourseSign.php
index f6ca196..d846f86 100755
--- a/app/Models/CourseSign.php
+++ b/app/Models/CourseSign.php
@@ -157,7 +157,7 @@ class CourseSign extends SoftDeletesModel
     public static function yhInvested($start_date = null, $end_date = null, $course_ids = null, $retList = false)
     {
         // 判断是否使用默认时间
-        $isDefaultDate = $start_date == CourseType::START_DATE || empty($course_ids);
+        $isDefaultDate = empty($start_date) || $start_date == CourseType::START_DATE || empty($course_ids);
         dd($isDefaultDate);
         // 获取学员ID列表
         if ($isDefaultDate) {