diff --git a/library/think/db/connector/Sqlsrv.php b/library/think/db/connector/Sqlsrv.php
index 1100f5dd..a63fb340 100644
--- a/library/think/db/connector/Sqlsrv.php
+++ b/library/think/db/connector/Sqlsrv.php
@@ -21,7 +21,6 @@ class Sqlsrv extends Connection
 {
     // PDO连接参数
     protected $params = [
-        PDO::ATTR_CASE              => PDO::CASE_LOWER,
         PDO::ATTR_ERRMODE           => PDO::ERRMODE_EXCEPTION,
         PDO::ATTR_STRINGIFY_FETCHES => false,
     ];