diff --git a/sourceCode/BQ_workpieceCornerExtraction.cpp b/sourceCode/BQ_workpieceCornerExtraction.cpp
index 3e24558..6aebc31 100644
--- a/sourceCode/BQ_workpieceCornerExtraction.cpp
+++ b/sourceCode/BQ_workpieceCornerExtraction.cpp
@@ -413,6 +413,11 @@ SSX_BQworkpieceResult sx_BQ_getWorkpieceCorners(
 	_getEdgeLinkingContour(&v_trees[idx0], true, firstPt, region[0].edgeLink_1, scanLines, true, workpieceParam.lineLen);
 	int idx1 = _getPointClosestContour(v_trees, true, lastPt, scanLines, true);
 	_getEdgeLinkingContour(&v_trees[idx1], true, lastPt, region[0].edgeLink_2, scanLines, true, workpieceParam.lineLen);
+	if ((region[0].edgeLink_1.size() < 5) || (region[0].edgeLink_2.size() < 5))
+	{
+		*errCode = SX_ERR_INVLD_EDGE_LINK_NUM;
+		return workpieceCorners;
+	}
 
 	region[1].rgnIdx = 1; //Top
 	_getEdgeContour(&v_trees[vTree_T], region[1].edge, scanLines, true);
@@ -423,7 +428,11 @@ SSX_BQworkpieceResult sx_BQ_getWorkpieceCorners(
 	_getEdgeLinkingContour(&h_trees[idx0], false, firstPt, region[1].edgeLink_1, scanLines, true, workpieceParam.lineLen);
 	idx1 = _getPointClosestContour(h_trees, false, lastPt, scanLines, true);
 	_getEdgeLinkingContour(&h_trees[idx1], false, lastPt, region[1].edgeLink_2, scanLines, true, workpieceParam.lineLen);
-
+	if ((region[1].edgeLink_1.size() < 5) || (region[1].edgeLink_2.size() < 5))
+	{
+		*errCode = SX_ERR_INVLD_EDGE_LINK_NUM;
+		return workpieceCorners;
+	}
 	region[2].rgnIdx = 2; //Right
 	_getEdgeContour(&h_trees[hTree_R], region[2].edge, scanLines, false);
 	//寻找对应的两边
@@ -433,7 +442,11 @@ SSX_BQworkpieceResult sx_BQ_getWorkpieceCorners(
 	_getEdgeLinkingContour(&v_trees[idx0], true, firstPt, region[2].edgeLink_1, scanLines, false, workpieceParam.lineLen);
 	idx1 = _getPointClosestContour(v_trees, true, lastPt, scanLines, false);
 	_getEdgeLinkingContour(&v_trees[idx1], true, lastPt, region[2].edgeLink_2, scanLines, false, workpieceParam.lineLen);
-
+	if ((region[2].edgeLink_1.size() < 5) || (region[2].edgeLink_2.size() < 5))
+	{
+		*errCode = SX_ERR_INVLD_EDGE_LINK_NUM;
+		return workpieceCorners;
+	}
 	region[3].rgnIdx = 3; //Bottom
 	_getEdgeContour(&v_trees[vTree_B], region[3].edge, scanLines, true);
 	//寻找对应的两边
@@ -443,6 +456,11 @@ SSX_BQworkpieceResult sx_BQ_getWorkpieceCorners(
 	_getEdgeLinkingContour(&h_trees[idx0], false, firstPt, region[3].edgeLink_1, scanLines, false, workpieceParam.lineLen);
 	idx1 = _getPointClosestContour(h_trees, false, lastPt, scanLines, true);
 	_getEdgeLinkingContour(&h_trees[idx1], false, lastPt, region[3].edgeLink_2, scanLines, false, workpieceParam.lineLen);
+	if ((region[3].edgeLink_1.size() < 5) || (region[3].edgeLink_2.size() < 5))
+	{
+		*errCode = SX_ERR_INVLD_EDGE_LINK_NUM;
+		return workpieceCorners;
+	}
 
 	for (int i = 0; i < 4; i++)
 	{
diff --git a/sourceCode/SG_errCode.h b/sourceCode/SG_errCode.h
index 111db32..e61d36e 100644
--- a/sourceCode/SG_errCode.h
+++ b/sourceCode/SG_errCode.h
@@ -9,4 +9,5 @@
 
 //BQ_workpiece
 #define SX_ERR_INVLD_VTREE_NUM		-2001
-#define SX_ERR_INVLD_HTREE_NUM		-2002
\ No newline at end of file
+#define SX_ERR_INVLD_HTREE_NUM		-2002
+#define SX_ERR_INVLD_EDGE_LINK_NUM	-2003
\ No newline at end of file