diff --git a/frontend/src/components/canvas/CanvasStage.vue b/frontend/src/components/canvas/CanvasStage.vue
index 75b2533..530ec0b 100644
--- a/frontend/src/components/canvas/CanvasStage.vue
+++ b/frontend/src/components/canvas/CanvasStage.vue
@@ -11,6 +11,9 @@ import {
   zoomAt,
   rectsIntersect,
   nodeRect,
+  BASE_SCALE,
+  MIN_SCALE,
+  MAX_SCALE,
 } from '../../utils/canvas'
 import CanvasNodeView from './CanvasNodeView.vue'
 
@@ -216,11 +219,11 @@ const edgePaths = computed(() => {
 })
 
 const worldStyle = computed(() => ({
-  transform: `translate3d(${vp.x}px, ${vp.y}px, 0) scale(${vp.scale})`,
+  transform: `translate3d(${vp.x}px, ${vp.y}px, 0) scale(${vp.scale * BASE_SCALE})`,
 }))
 
 const gridStyle = computed(() => {
-  const cell = Math.max(14, 24 * vp.scale)
+  const cell = Math.max(14, 24 * vp.scale * BASE_SCALE)
   return {
     backgroundSize: `${cell}px ${cell}px`,
     backgroundPosition: `${vp.x}px ${vp.y}px`,
@@ -645,8 +648,9 @@ function zoomTo(scale) {
 }
 function centerOn(x, y) {
   const r = stageEl.value?.getBoundingClientRect()
-  vp.x = (r ? r.width / 2 : 400) - x * vp.scale
-  vp.y = (r ? r.height / 2 : 300) - y * vp.scale
+  const s = vp.scale * BASE_SCALE
+  vp.x = (r ? r.width / 2 : 400) - x * s
+  vp.y = (r ? r.height / 2 : 300) - y * s
   notifyViewport()
 }
 function clearSelection() {
@@ -677,8 +681,8 @@ function fitToContent() {
   const pad = 80
   const bw = Math.max(1, x2 - x1 + pad * 2)
   const bh = Math.max(1, y2 - y1 + pad * 2)
-  const s = Math.min(sw / bw, sh / bh, 1.2)
-  vp.scale = s
+  const s = Math.min(sw / bw, sh / bh, 1.2) // 期望的有效缩放
+  vp.scale = Math.min(MAX_SCALE, Math.max(MIN_SCALE, s / BASE_SCALE))
   vp.x = sw / 2 - (x1 - pad + bw / 2) * s
   vp.y = sh / 2 - (y1 - pad + bh / 2) * s
   notifyViewport()
diff --git a/frontend/src/utils/canvas.js b/frontend/src/utils/canvas.js
index 7dc0b8c..ad2c8fe 100644
--- a/frontend/src/utils/canvas.js
+++ b/frontend/src/utils/canvas.js
@@ -7,17 +7,21 @@ let idSeq = 0
 
 /** 世界→屏幕 */
 export function worldToScreen(x, y, vp) {
-  return { x: x * vp.scale + vp.x, y: y * vp.scale + vp.y }
+  const s = vp.scale * BASE_SCALE
+  return { x: x * s + vp.x, y: y * s + vp.y }
 }
 
 /** 屏幕→世界 */
 export function screenToWorld(sx, sy, vp) {
-  return { x: (sx - vp.x) / vp.scale, y: (sy - vp.y) / vp.scale }
+  const s = vp.scale * BASE_SCALE
+  return { x: (sx - vp.x) / s, y: (sy - vp.y) / s }
 }
 
 export const MIN_SCALE = 0.05
 export const MAX_SCALE = 4
-export const DEFAULT_SCALE = 0.6 // 新画布/重置视图的默认缩放
+export const DEFAULT_SCALE = 1 // 新画布/重置视图的逻辑缩放(BASE_SCALE 已整体缩小)
+// 视觉基准:显示 100% 时实际渲染 0.6×,全部屏幕换算统一走它
+export const BASE_SCALE = 0.6
 
 /** 以屏幕点 m 为锚缩放到 newScale,返回新 viewport(平移量按锚点保持不动) */
 export function zoomAt(vp, mx, my, newScale) {
@@ -41,11 +45,12 @@ export function pointInRect(px, py, r) {
 
 /** 视口剔除:返回与可见世界矩形(含 margin)相交的节点。纯几何,千级节点也是微秒。 */
 export function nodesInViewport(nodes, vp, stageW, stageH, margin = 240) {
+  const s = vp.scale * BASE_SCALE
   const vis = {
-    x: -vp.x / vp.scale - margin,
-    y: -vp.y / vp.scale - margin,
-    w: stageW / vp.scale + margin * 2,
-    h: stageH / vp.scale + margin * 2,
+    x: -vp.x / s - margin,
+    y: -vp.y / s - margin,
+    w: stageW / s + margin * 2,
+    h: stageH / s + margin * 2,
   }
   return nodes.filter((n) => rectsIntersect(nodeRect(n), vis))
 }