diff --git a/backend/internal/handler/ticket.go b/backend/internal/handler/ticket.go
index a2f9343..41f7f12 100644
--- a/backend/internal/handler/ticket.go
+++ b/backend/internal/handler/ticket.go
@@ -219,6 +219,16 @@ func CreateTicket(c *gin.Context) {
 		return
 	}
 
+	// Reject read-only SQL statements (SELECT/SHOW/DESC/EXPLAIN)
+	upperSQL := strings.ToUpper(strings.TrimSpace(input.SQLContent))
+	readOnlyPrefixes := []string{"SELECT", "SHOW", "DESC", "DESCRIBE", "EXPLAIN"}
+	for _, prefix := range readOnlyPrefixes {
+		if strings.HasPrefix(upperSQL, prefix) {
+			c.JSON(http.StatusBadRequest, gin.H{"detail": "数据变更工单不支持 SELECT/SHOW/DESC 等只读语句，请使用查询数据功能"})
+			return
+		}
+	}
+
 	// Auto-fill workflow_id from instance if not provided
 	if input.WorkflowID == nil || *input.WorkflowID == 0 {
 		var inst model.Instance
diff --git a/frontend/src/pages/TicketCreatePage.tsx b/frontend/src/pages/TicketCreatePage.tsx
index 9e8487a..0df818b 100644
--- a/frontend/src/pages/TicketCreatePage.tsx
+++ b/frontend/src/pages/TicketCreatePage.tsx
@@ -180,6 +180,15 @@ export default function TicketCreatePage() {
     if (!instanceId) { setError('请选择目标实例'); return; }
     if (!database) { setError('请选择数据库'); return; }
 
+    // 前端拦截只读语句
+    const upperSQL = sqlContent.trim().toUpperCase();
+    const readOnlyPrefixes = ['SELECT', 'SHOW', 'DESC', 'DESCRIBE', 'EXPLAIN'];
+    if (readOnlyPrefixes.some(p => upperSQL.startsWith(p))) {
+      setError('数据变更工单不支持 SELECT/SHOW/DESC 等只读语句，请使用查询数据功能');
+      setValidated(false);
+      return;
+    }
+
     setError(''); setAuditResult(null); setValidating(true);
     try {
       const result = await ticketApi.audit({
@@ -212,6 +221,14 @@ export default function TicketCreatePage() {
     if (!sqlContent.trim()) { setError('请填写 SQL 语句'); return; }
     if (!reason.trim()) { setError('请填写变更原因'); return; }
 
+    // 前端拦截只读语句
+    const upperSQL = sqlContent.trim().toUpperCase();
+    const readOnlyPrefixes = ['SELECT', 'SHOW', 'DESC', 'DESCRIBE', 'EXPLAIN'];
+    if (readOnlyPrefixes.some(p => upperSQL.startsWith(p))) {
+      setError('数据变更工单不支持 SELECT/SHOW/DESC 等只读语句，请使用查询数据功能');
+      return;
+    }
+
     setError(''); setSubmitting(true);
 
     try {