diff --git a/src/hooks/usePolygon.js b/src/hooks/usePolygon.js
index 84f8e9bf..463be9f2 100644
--- a/src/hooks/usePolygon.js
+++ b/src/hooks/usePolygon.js
@@ -1,14 +1,7 @@
 import { ANGLE_TYPE, canvasState, currentAngleTypeSelector, pitchTextSelector } from '@/store/canvasAtom'
 import { useRecoilValue } from 'recoil'
 import { fabric } from 'fabric'
-import {
-  distanceBetweenPoints,
-  findAndRemoveClosestPoint,
-  getDegreeByChon,
-  getDegreeInOrientation,
-  isPointOnLine,
-  toFixedWithoutRounding,
-} from '@/util/canvas-util'
+import { findAndRemoveClosestPoint, getDegreeByChon, getDegreeInOrientation, isPointOnLine } from '@/util/canvas-util'
 import { QPolygon } from '@/components/fabric/QPolygon'
 import { isSamePoint, removeDuplicatePolygons } from '@/util/qpolygon-utils'
 import { flowDisplaySelector } from '@/store/settingAtom'
@@ -1073,8 +1066,14 @@ export const usePolygon = () => {
       )
     })
 
+    allLines = allLines.filter((line) => {
+      return Math.abs(line.startPoint.x - line.endPoint.x) > 2 || Math.abs(line.startPoint.y - line.endPoint.y) > 2
+    })
+
     // 나눠서 중복 제거된 roof return
-    const newRoofs = getSplitRoofsPoints(allLines)
+    let newRoofs = getSplitRoofsPoints(allLines)
+
+    newRoofs = newRoofs.filter((roof) => roof.length !== 0)
 
     newRoofs.forEach((roofPoint, index) => {
       let defense, pitch
@@ -1212,10 +1211,45 @@ export const usePolygon = () => {
   }
 
   const getSplitRoofsPoints = (allLines) => {
+    // 모든 좌표점들을 수집
+    const allPoints = []
+    allLines.forEach((line, lineIndex) => {
+      allPoints.push({ point: line.startPoint, lineIndex, pointType: 'start' })
+      allPoints.push({ point: line.endPoint, lineIndex, pointType: 'end' })
+    })
+
+    // X 좌표 통일
+    for (let i = 0; i < allPoints.length; i++) {
+      for (let j = i + 1; j < allPoints.length; j++) {
+        const point1 = allPoints[i].point
+        const point2 = allPoints[j].point
+
+        if (Math.abs(point1.x - point2.x) < 1) {
+          const maxX = Math.max(point1.x, point2.x)
+          point1.x = maxX
+          point2.x = maxX
+        }
+      }
+    }
+
+    // Y 좌표 통일
+    for (let i = 0; i < allPoints.length; i++) {
+      for (let j = i + 1; j < allPoints.length; j++) {
+        const point1 = allPoints[i].point
+        const point2 = allPoints[j].point
+
+        if (Math.abs(point1.y - point2.y) < 1) {
+          const maxY = Math.max(point1.y, point2.y)
+          point1.y = maxY
+          point2.y = maxY
+        }
+      }
+    }
+
     // ==== Utility functions ====
 
     function isSamePoint(p1, p2, epsilon = 1) {
-      return Math.abs(p1.x - p2.x) <= 2 && Math.abs(p1.y - p2.y) <= 2
+      return Math.abs(p1.x - p2.x) <= epsilon && Math.abs(p1.y - p2.y) <= epsilon
     }
 
     function normalizePoint(p, epsilon = 1) {
@@ -1241,6 +1275,7 @@ export const usePolygon = () => {
       const startKey = pointToKey(start, epsilon)
       return (graph[startKey] || []).some((neighbor) => isSamePoint(neighbor.point, end, epsilon))
     }
+
     // ==== Dijkstra pathfinding ====
 
     function findShortestPath(start, end, graph, epsilon = 1) {
@@ -1329,11 +1364,15 @@ export const usePolygon = () => {
       }
 
       const startPoint = { ...line.startPoint } // 시작점
+
       let arrivalPoint = { ...line.endPoint } // 도착점
       roofs.push(getPath(startPoint, arrivalPoint, graph))
     })
 
-    return removeDuplicatePolygons(roofs.filter((roof) => roof.length < 100))
+    return removeDuplicatePolygons(
+      roofs.filter((roof) => roof.length < 100),
+      allLines.some((line) => line.name === 'auxiliaryLine'),
+    )
   }
 
   const splitPolygonWithSeparate = (separates) => {
diff --git a/src/util/qpolygon-utils.js b/src/util/qpolygon-utils.js
index 610d043d..72ea0db0 100644
--- a/src/util/qpolygon-utils.js
+++ b/src/util/qpolygon-utils.js
@@ -292,7 +292,7 @@ function arePolygonsEqual(polygon1, polygon2) {
   return normalizedPolygon1.every((point, index) => arePointsEqual(point, normalizedPolygon2[index]))
 }
 
-export function removeDuplicatePolygons(polygons) {
+export function removeDuplicatePolygons(polygons, hasAuxiliaryLine = false) {
   let uniquePolygons = []
 
   // x가 전부 같거나, y가 전부 같은 경우 제거
@@ -303,9 +303,11 @@ export function removeDuplicatePolygons(polygons) {
     }
   })
 
-  uniquePolygons = uniquePolygons.filter((polygon) => {
-    return isValidPoints(polygon)
-  })
+  if (!hasAuxiliaryLine) {
+    uniquePolygons = uniquePolygons.filter((polygon) => {
+      return isValidPoints(polygon)
+    })
+  }
 
   return uniquePolygons
 }