diff --git a/pipeline_bidding/bid_flow.py b/pipeline_bidding/bid_flow.py
index a2c4f77..58c4bd8 100644
--- a/pipeline_bidding/bid_flow.py
+++ b/pipeline_bidding/bid_flow.py
@@ -176,9 +176,16 @@ async def _open_dim_tasks(sor, project_id, dim):
 
 
 async def _tender_text_len(sor, project_id):
-    """项目最新招标文件正文字符数（无文件/无正文返回 0）。拆解阈值判定用。"""
+    """项目最新招标文件正文字符数（无文件/无正文返回 0）。拆解阈值判定用。
+
+    ⚠️ 必须 CHAR_LENGTH（字符）不能 LENGTH（字节）：抽取工具按 Python 字符串
+    索引切片（txt[offset:offset+length]），char_range 区间是字符坐标。甘肃实测
+    LENGTH=179031 vs CHAR_LENGTH=67658（CJK utf8mb4 ≈2.65字节/字）——按字节拆
+    3 段时第 2 段仅尾部 8k 字符有效、第 3 段完全越界读空串（2026-09-15 四维度
+    拆解"实测通过"实际带病运行：区间错位浪费 1/3 子任务，2026-09-18 tech 接入时修正）。
+    """
     recs = await sor.sqlExe(
-        "SELECT LENGTH(content_text) AS n FROM bid_tender_files "
+        "SELECT CHAR_LENGTH(content_text) AS n FROM bid_tender_files "
         "WHERE project_id=${p}$ ORDER BY created_at DESC LIMIT 1", {"p": project_id})
     await sor.sqlExe("COMMIT", {})
     if not recs:
@@ -1537,28 +1544,46 @@ async def _reconcile_tech_analysis_qc(sor, project_id, pname, n_items, latest_qc
             return False, False, True
         qc_imp = (latest_qc.get("improvement") or "") if (
             latest_qc and str(latest_qc.get("passed")) != "1") else ""
-        attempts = await _count(
-            sor, "SELECT COUNT(*) AS c FROM pipeline_tasks WHERE tenant_id=${p}$ "
-                 "AND pipeline_id='role_task' AND role=${r}$ AND state IN "
-                 "('approved','completed','qc_rejected') AND params LIKE ${kw}$",
-            {"p": project_id, "r": R_ANALYST, "kw": '%bid_tech_analysis%'})
-        if attempts >= MAX_ANALYST_ATTEMPT + th["qc_max_round"]:
+        # 轮次口径（2026-09-18 拆解配套，四维度 A 块同款）：一个拆解轮派 N 个分段
+        # 子任务（同 round 标签），按任务条数计轮会把一轮误算 N 轮触发上限误判。
+        # 旧口径 COUNT(params LIKE '%bid_tech_analysis%') 数条数，拆解后同样虚高。
+        n_first = await _dim_round_count(sor, project_id, TECH_KIND, redo=False)
+        n_redo = await _dim_round_count(sor, project_id, TECH_KIND, redo=True)
+        _over = (n_redo >= th["qc_max_round"]) if qc_imp else (n_first >= MAX_ANALYST_ATTEMPT)
+        if _over:
             ht = await find_human_task(sor, project_id, "general", status="pending")
             if not ht:
                 await create_human_task(
                     sor, project_id, "general",
-                    "技术评估项解析多次未产出，需人工介入：%s" % pname,
-                    ("技术评估项解析任务已执行 %d 次，产出仍为空。\n"
+                    "技术评估项解析多轮未产出，需人工介入：%s" % pname,
+                    ("技术评估项解析已执行 %d 轮（首跑 %d / QC重做 %d），产出仍为空或未过审。\n"
                      "请检查招标文件技术部分是否可读（bid_tender_files.content_text），"
-                     "或用 list_tech_items/add_tech_item 人工补录评估项。" % attempts),
+                     "或用 list_tech_items/add_tech_item 人工补录评估项。"
+                     % (n_first + n_redo, n_first, n_redo)),
                     assignee_role="owner.superuser")
                 await sor.sqlExe("COMMIT", {})
-            acts.append("escalated: 技术评估项解析重试超限 → 人工介入")
+            acts.append("escalated: 技术评估项解析轮次超限 → 人工介入")
             return False, False, True
         tparams = {"stage": "tech_analysis", "task_kind": "bid_tech_analysis",
                    "analysis_dim": TECH_KIND, "flow_key": flow_key}
         if qc_imp:
             tparams["qc_redo"] = 1
+        # 大文件机械拆解（2026-09-18 用户要求，四维度 A 块同款机制）：正文超阈值
+        # → 拆 N 段并行子任务，char_range 互不重叠。单体全文抽取实测弊病（甘肃 r1）：
+        # 2.7 小时串行 + agent 自选 offset 步进造成窗口大量重叠，(category,item_name)
+        # 精确去重对跨窗口近义命名失效 → 733 条注水（QC 6.8 退回，判重复条目/source_ref
+        # 不可回溯）。不相交区间从源头消除跨窗口重复。
+        _tlen = await _tender_text_len(sor, project_id)
+        if _tlen > th["split_chars"]:
+            _ids = await _create_split_tasks(
+                sor, project_id, TECH_KIND, "技术评估项抽取", pname, tparams, _tlen,
+                th["split_chars"], ("redo%d" % (n_redo + 1)) if qc_imp else "run1",
+                qc_imp=["[tech_items] %s" % qc_imp[:2000]] if qc_imp else None)
+            await sor.sqlExe("COMMIT", {})
+            acts.append("created: 技术评估项抽取拆解 %d 个分段子任务（正文 %d 字符%s）"
+                        % (len(_ids), _tlen, "，QC退回重做" if qc_imp else ""))
+            return False, False, True
+        if qc_imp:
             tparams["qc_improvements"] = ["[tech_items] %s" % qc_imp[:2000]]
         tid = await create_role_task(
             sor, project_id, R_ANALYST,