diff --git a/web/hwlab-cloud-web/scripts/agent-observer-contract.test.ts b/web/hwlab-cloud-web/scripts/agent-observer-contract.test.ts
index 5ef315aa..ae75d83b 100644
--- a/web/hwlab-cloud-web/scripts/agent-observer-contract.test.ts
+++ b/web/hwlab-cloud-web/scripts/agent-observer-contract.test.ts
@@ -27,9 +27,16 @@ test("Agent observer relation tree consumes the YAML node limit", () => {
   assert.equal(window.rows.length, 3);
 });
 
+test("Agent observer relation tree keeps a stable order across live activity reordering", () => {
+  const first = buildRelationWindow([observerRun("run_2"), observerRun("run_1")], null, new Set(), new Set(), 10);
+  const second = buildRelationWindow([observerRun("run_1"), observerRun("run_2")], null, new Set(), new Set(), 10);
+  assert.deepEqual(first.rows.map((row) => row.id), second.rows.map((row) => row.id));
+});
+
 function observerRun(id: string): AgentObserverRun {
   return {
     id,
+    title: null,
     taskId: null,
     taskStatus: null,
     commandId: null,
diff --git a/web/hwlab-cloud-web/src/components/agents/AgentRunMindMap.vue b/web/hwlab-cloud-web/src/components/agents/AgentRunMindMap.vue
index ee801755..ac616e69 100644
--- a/web/hwlab-cloud-web/src/components/agents/AgentRunMindMap.vue
+++ b/web/hwlab-cloud-web/src/components/agents/AgentRunMindMap.vue
@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { computed, nextTick } from "vue";
+import { computed, nextTick, onMounted, ref, watch } from "vue";
 import dagre from "@dagrejs/dagre";
 import { Handle, MarkerType, Position, VueFlow, useVueFlow, type Edge, type Node } from "@vue-flow/core";
 import { Focus, Minus, Plus } from "lucide-vue-next";
@@ -32,23 +32,35 @@ const emit = defineEmits<{
 const flowId = "agentrun-mind-map";
 const { fitView, zoomIn, zoomOut } = useVueFlow({ id: flowId });
 const runById = computed(() => new Map(props.runs.map((run) => [run.id, run])));
+const layoutCache = new Map<string, Map<string, { x: number; y: number }>>();
+const initialFitDone = ref(false);
 
 const graph = computed(() => {
-  const layout = new dagre.graphlib.Graph().setDefaultEdgeLabel(() => ({}));
-  layout.setGraph({ rankdir: "LR", ranksep: 74, nodesep: 24, edgesep: 12, marginx: 32, marginy: 32 });
-
-  for (const row of props.rows) layout.setNode(row.id, { width: nodeWidth(row), height: 70 });
-  for (const row of props.rows) if (row.parentId && layout.hasNode(row.parentId)) layout.setEdge(row.parentId, row.id);
-  dagre.layout(layout);
+  // 状态和消息更新只刷新节点内容，不重新计算位置。
+  const layoutKey = props.rows.map((row) => `${row.id}|${row.parentId ?? ""}|${row.kind}|${row.childCount}|${row.expanded}`).join("\n");
+  let positions = layoutCache.get(layoutKey);
+  if (!positions) {
+    const layout = new dagre.graphlib.Graph().setDefaultEdgeLabel(() => ({}));
+    layout.setGraph({ rankdir: "LR", ranksep: 74, nodesep: 24, edgesep: 12, marginx: 32, marginy: 32 });
+    for (const row of props.rows) layout.setNode(row.id, { width: nodeWidth(row), height: 70 });
+    for (const row of props.rows) if (row.parentId && layout.hasNode(row.parentId)) layout.setEdge(row.parentId, row.id);
+    dagre.layout(layout);
+    positions = new Map(props.rows.map((row) => {
+      const position = layout.node(row.id);
+      return [row.id, { x: position.x - position.width / 2, y: position.y - position.height / 2 }];
+    }));
+    layoutCache.set(layoutKey, positions);
+    if (layoutCache.size > 8) layoutCache.delete(layoutCache.keys().next().value!);
+  }
 
   const nodes: Node<MindMapNodeData>[] = props.rows.map((row) => {
-    const position = layout.node(row.id);
+    const position = positions.get(row.id) ?? { x: 0, y: 0 };
     const run = row.runId ? runById.value.get(row.runId) : undefined;
     const title = row.kind === "run" && run?.title ? run.title : row.label;
     return {
       id: row.id,
       type: "observer",
-      position: { x: position.x - position.width / 2, y: position.y - position.height / 2 },
+      position,
       sourcePosition: Position.Right,
       targetPosition: Position.Left,
       selectable: false,
@@ -57,7 +69,7 @@ const graph = computed(() => {
     };
   });
   const edges: Edge[] = props.rows
-    .filter((row) => row.parentId && layout.hasNode(row.parentId))
+    .filter((row) => row.parentId && positions.has(row.parentId))
     .map((row) => ({
       id: `${row.parentId}->${row.id}`,
       source: row.parentId!,
@@ -89,6 +101,15 @@ async function fit(): Promise<void> {
   await nextTick();
   await fitView({ padding: 0.14, duration: 220, maxZoom: 1 });
 }
+
+async function fitInitial(): Promise<void> {
+  if (initialFitDone.value || !props.rows.length) return;
+  await fit();
+  initialFitDone.value = true;
+}
+
+watch(() => graph.value.nodes.length, () => { void fitInitial(); }, { flush: "post" });
+onMounted(() => { void fitInitial(); });
 </script>
 
 <template>
@@ -103,7 +124,7 @@ async function fit(): Promise<void> {
       :nodes-draggable="false"
       :nodes-connectable="false"
       :elements-selectable="false"
-      fit-view-on-init
+      :fit-view-on-init="false"
       class="agent-mind-map-flow"
       aria-label="AgentRun 思维导图"
     >
diff --git a/web/hwlab-cloud-web/src/stores/agent-observer.ts b/web/hwlab-cloud-web/src/stores/agent-observer.ts
index 54245523..bee8376f 100644
--- a/web/hwlab-cloud-web/src/stores/agent-observer.ts
+++ b/web/hwlab-cloud-web/src/stores/agent-observer.ts
@@ -591,7 +591,8 @@ export function buildRelationWindow(
   });
 
   let omittedRunCount = 0;
-  for (const [runIndex, run] of runs.entries()) {
+  const stableRuns = [...runs].sort((left, right) => compareText(relationRunOrderKey(left), relationRunOrderKey(right)));
+  for (const [runIndex, run] of stableRuns.entries()) {
     const hasCompleteContainment = Boolean((run.projectId || run.workspace) && run.sessionId && run.taskId);
     const scopeId = hasCompleteContainment ? relationId("scope", `${run.projectId ?? ""}\u0000${run.workspace ?? ""}`) : unassociatedId;
     const sessionId = hasCompleteContainment && run.sessionId ? relationId("session", `${scopeId}\u0000${run.sessionId}`) : null;
@@ -603,7 +604,7 @@ export function buildRelationWindow(
     const commandId = run.commandId ? relationId("command", `${commandParentId}\u0000${run.commandId}`) : null;
     const missingNodeCount = [scopeId, sessionId, taskId, runNodeId, attemptId, commandId].filter((id): id is string => typeof id === "string" && !nodes.has(id)).length;
     if (nodes.size + missingNodeCount > nodeLimit) {
-      omittedRunCount = runs.length - runIndex;
+      omittedRunCount = stableRuns.length - runIndex;
       break;
     }
     let parent = hasCompleteContainment
@@ -713,6 +714,14 @@ function relationId(kind: AgentObserverRelationKind, value: string): string {
   return `${kind}:${encodeURIComponent(value)}`;
 }
 
+function relationRunOrderKey(run: AgentObserverRun): string {
+  return [run.projectId, run.workspace, run.sessionId, run.taskId, run.id].map((value) => value ?? "").join("\u0000");
+}
+
+function compareText(left: string, right: string): number {
+  return left < right ? -1 : left > right ? 1 : 0;
+}
+
 function latestTimestamp(previous: string | null, next: string | null): string | null {
   if (!previous) return next;
   if (!next) return previous;