diff --git a/ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/service/impl/SysTenantServiceImpl.java b/ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/service/impl/SysTenantServiceImpl.java
index aee18f76c..9a8706863 100644
--- a/ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/service/impl/SysTenantServiceImpl.java
+++ b/ruoyi-modules/ruoyi-system/src/main/java/org/dromara/system/service/impl/SysTenantServiceImpl.java
@@ -264,6 +264,12 @@ public class SysTenantServiceImpl implements ISysTenantService {
         SysTenant tenant = MapstructUtils.convert(bo, SysTenant.class);
         tenant.setTenantId(null);
         tenant.setPackageId(null);
+
+        String domain = tenant.getDomain();
+        if (domain != null && !domain.isBlank()) {
+            tenant.setDomain(domain.toLowerCase());
+        }
+
         return baseMapper.updateById(tenant) > 0;
     }