diff --git a/.github/PULL_REQUEST_TEMPLATE.md b/.github/PULL_REQUEST_TEMPLATE.md
index c9a048e6a..4a6ba7d3c 100644
--- a/.github/PULL_REQUEST_TEMPLATE.md
+++ b/.github/PULL_REQUEST_TEMPLATE.md
@@ -13,6 +13,7 @@
 
 ## Required Verification
 
+- [ ] `pnpm check:branch`
 - [ ] `pnpm check:quality`
 - [ ] `AUTH_TRUST_HOST=true PORT=3001 pnpm dev`
 - [ ] `SMOKE_BASE_URL=http://127.0.0.1:3001 pnpm smoke:routes`
diff --git a/README.md b/README.md
index 5e8ac55db..df4096091 100644
--- a/README.md
+++ b/README.md
@@ -72,6 +72,7 @@ pnpm lint
 pnpm check:logs
 pnpm check:brand
 pnpm check:ci
+pnpm check:branch
 pnpm check:env
 pnpm check:secrets
 pnpm check:metadata
@@ -91,6 +92,8 @@ pnpm db:generate
 推荐提交前至少运行：
 
 ```bash
+git fetch github main --prune
+pnpm check:branch
 pnpm check:quality
 pnpm audit:security
 AUTH_TRUST_HOST=true PORT=3001 pnpm dev
diff --git a/docs/operations.md b/docs/operations.md
index c79fb30c4..e45dfb182 100644
--- a/docs/operations.md
+++ b/docs/operations.md
@@ -5,6 +5,8 @@
 ## 合并前检查
 
 ```bash
+git fetch github main --prune
+pnpm check:branch
 pnpm lint
 pnpm check:logs
 pnpm check:brand
@@ -40,6 +42,21 @@ SMOKE_BASE_URL=http://127.0.0.1:3001 pnpm verify:release
 
 `pnpm clean:artifacts` 会清理当前工作区常见本地垃圾文件，例如 `.DS_Store`、swap 文件和 `tsconfig.tsbuildinfo`。它会跳过 `.git`、`node_modules`、`.next`、`.pnpm-store`、`.venv` 等重目录，适合在提交或打包前手动执行。
 
+## 分支与 PR 就绪检查
+
+```bash
+git fetch github main --prune
+pnpm check:branch
+```
+
+`pnpm check:branch` 默认以 `github/main` 为基线，检查当前工作区是否干净、基线 ref 是否存在、当前分支相对 main 的 ahead/behind 状态、受影响文件数量，以及 dry-run merge tree 是否出现冲突标记。它会把 behind main 作为 warning，方便还没决定 rebase/merge 前先看风险；如果发布或合并策略要求必须最新，可使用：
+
+```bash
+REQUIRE_UP_TO_DATE=true pnpm check:branch
+```
+
+如果远端名不同，可以用 `PR_BASE_REF=origin/main pnpm check:branch` 或 `pnpm check:branch origin/main` 覆盖基线。提交前临时验证未提交改动时，可使用 `ALLOW_DIRTY=true pnpm check:branch` 或 `pnpm check:branch --allow-dirty`。
+
 ## CI
 
 `.github/workflows/lint.yml` 是基础质量门禁，运行 `pnpm check:quality`，负责 lint、日志治理、公开交付面品牌治理、CI hygiene、环境变量示例卫生、secret hygiene、package metadata、测试门禁卫生、轻量 helper 回归测试、类型检查、diff hygiene 和 tracked 污染物检查。
diff --git a/docs/release-readiness.md b/docs/release-readiness.md
index 185d679fb..a48b37f87 100644
--- a/docs/release-readiness.md
+++ b/docs/release-readiness.md
@@ -6,6 +6,8 @@
 
 ```bash
 pnpm install --frozen-lockfile
+git fetch github main --prune
+pnpm check:branch
 AUTH_TRUST_HOST=true PORT=3001 pnpm dev
 SMOKE_BASE_URL=http://127.0.0.1:3001 pnpm verify:release
 ```
@@ -13,6 +15,7 @@ SMOKE_BASE_URL=http://127.0.0.1:3001 pnpm verify:release
 预期：
 
 - `pnpm check:quality` 通过 lint、日志脱敏门禁、公开交付面品牌治理、CI hygiene、环境变量示例卫生、secret hygiene、package metadata、测试门禁卫生、轻量 helper 回归测试、类型检查、diff hygiene 和 tracked 污染物检查。
+- `pnpm check:branch` 确认当前分支相对 `github/main` 没有 dry-run merge 冲突；behind main 会提示为 warning，发布前可用 `REQUIRE_UP_TO_DATE=true` 提升为失败。
 - `pnpm audit:security` 输出已审计，Dependency Audit workflow 也应通过；若仍有 critical/high，必须在 [dependency-risk-register.md](dependency-risk-register.md) 中记录 remediation 或风险接受状态。
 - `pnpm smoke:routes` 验证 `/` 返回 200。
 - `/classic` 和 `/chat/test-id` 重定向到 `/`。
diff --git a/package.json b/package.json
index b1667722d..05563e839 100644
--- a/package.json
+++ b/package.json
@@ -20,6 +20,7 @@
     "check:artifacts": "node scripts/check-tracked-artifacts.mjs",
     "check:brand": "node scripts/check-brand-hygiene.mjs",
     "check:ci": "node scripts/check-ci-hygiene.mjs",
+    "check:branch": "node scripts/check-branch-readiness.mjs",
     "check:env": "node scripts/check-env-example.mjs",
     "check:secrets": "node scripts/check-secrets.mjs",
     "check:metadata": "node scripts/check-package-metadata.mjs",
diff --git a/scripts/check-branch-readiness.mjs b/scripts/check-branch-readiness.mjs
new file mode 100644
index 000000000..8a21984fd
--- /dev/null
+++ b/scripts/check-branch-readiness.mjs
@@ -0,0 +1,104 @@
+#!/usr/bin/env node
+
+import { execFileSync } from "node:child_process";
+import { writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+const args = process.argv.slice(2);
+const baseRef = process.env.PR_BASE_REF || args.find((arg) => !arg.startsWith("--")) || "github/main";
+const requireUpToDate =
+  process.env.REQUIRE_UP_TO_DATE === "true" || args.includes("--require-up-to-date");
+const allowDirty = process.env.ALLOW_DIRTY === "true" || args.includes("--allow-dirty");
+
+const failures = [];
+const warnings = [];
+
+const currentBranch = git(["branch", "--show-current"]).trim() || "HEAD";
+const status = git(["status", "--porcelain"]);
+if (status.trim() && !allowDirty) {
+  failures.push("working tree has uncommitted changes; commit, stash, or set ALLOW_DIRTY=true");
+}
+
+try {
+  git(["rev-parse", "--verify", baseRef]);
+} catch {
+  failures.push(`base ref not found: ${baseRef}. Run \`git fetch\` or set PR_BASE_REF.`);
+}
+
+if (failures.length === 0) {
+  const mergeBase = git(["merge-base", "HEAD", baseRef]).trim();
+  const [behindText, aheadText] = git(["rev-list", "--left-right", "--count", `${baseRef}...HEAD`])
+    .trim()
+    .split(/\s+/);
+  const behind = Number.parseInt(behindText || "0", 10);
+  const ahead = Number.parseInt(aheadText || "0", 10);
+  const changedFiles = git(["diff", "--name-only", `${baseRef}...HEAD`])
+    .split(/\r?\n/)
+    .filter(Boolean).length;
+
+  const mergeTree = runMergeTree(mergeBase, baseRef);
+  const conflictLines = mergeTree
+    .split(/\r?\n/)
+    .filter((line) => /^(<<<<<<<|=======|>>>>>>>|CONFLICT\b)/.test(line));
+
+  if (conflictLines.length > 0) {
+    const conflictReportPath = join(tmpdir(), "yedir-branch-readiness-conflicts.txt");
+    writeFileSync(conflictReportPath, conflictLines.join("\n"));
+    failures.push(
+      `merge conflict markers detected against ${baseRef}; details: ${conflictReportPath}`
+    );
+  }
+
+  if (behind > 0) {
+    const message = `${currentBranch} is behind ${baseRef} by ${behind} commit(s)`;
+    if (requireUpToDate) {
+      failures.push(message);
+    } else {
+      warnings.push(message);
+    }
+  }
+
+  console.log(
+    JSON.stringify(
+      {
+        baseRef,
+        branch: currentBranch,
+        mergeBase,
+        ahead,
+        behind,
+        changedFiles,
+        mergeConflictMarkers: conflictLines.length,
+        requireUpToDate,
+      },
+      null,
+      2
+    )
+  );
+}
+
+if (warnings.length > 0) {
+  console.warn(`Branch readiness warnings:\n- ${warnings.join("\n- ")}`);
+}
+
+if (failures.length > 0) {
+  console.error(`Branch readiness failed:\n- ${failures.join("\n- ")}`);
+  process.exit(1);
+}
+
+console.log("Branch readiness check passed.");
+
+function git(args) {
+  return execFileSync("git", args, {
+    encoding: "utf8",
+    stdio: ["ignore", "pipe", "pipe"],
+  });
+}
+
+function runMergeTree(mergeBase, baseRef) {
+  try {
+    return git(["merge-tree", mergeBase, "HEAD", baseRef]);
+  } catch (error) {
+    return [error.stdout, error.stderr].filter(Boolean).join("\n");
+  }
+}