diff --git a/analyzer/java/ext.go b/analyzer/java/ext.go
index 6a44f602cee6c36eae347ca2c64864c45e59713f..ff1e6cc5f4b3385831566c34c28e6170dddd81ac 100644
--- a/analyzer/java/ext.go
+++ b/analyzer/java/ext.go
@@ -127,12 +127,12 @@ func buildMvnDepTree(lines []string) *model.DepTree {
 	for _, line := range lines {
 		// 计算层级
 		level := 0
+		for level*3+2 < len(line) && line[level*3+2] == ' ' {
+			level++
+		}
 		if level*3+2 >= len(line) {
 			continue
 		}
-		for line[level*3+2] == ' ' {
-			level++
-		}
 		root = tops[len(tops)-1]
 		tags := strings.Split(line[level*3:], ":")
 		if len(tags) < 4 {