diff --git a/library/think/db/builder/Pgsql.php b/library/think/db/builder/Pgsql.php
index 6f256e0e..0a955a5b 100644
--- a/library/think/db/builder/Pgsql.php
+++ b/library/think/db/builder/Pgsql.php
@@ -50,7 +50,7 @@ class Pgsql extends Builder
         $key = trim($key);
         if (strpos($key, '$.') && false === strpos($key, '(')) {
             // JSON字段支持
-            list($field, $name) = explode($key, '$.');
+            list($field, $name) = explode('$.', $key);
             $key                = $field . '->>\'' . $name . '\'';
         }
         return $key;