diff --git a/src/genesis/qa/validator.py b/src/genesis/qa/validator.py
new file mode 100644
index 0000000..c4fc545
--- /dev/null
+++ b/src/genesis/qa/validator.py
@@ -0,0 +1,31 @@
+"""QA 校验：章节级/文档级评估（Phase 5）。"""
+from __future__ import annotations
+
+from genesis.eval.scorer import ChapterScorer, EvalReport, ChapterArtifact
+from genesis.writer.models import ChapterContent
+
+
+class QAValidator:
+    def __init__(self, scorer: ChapterScorer | None = None) -> None:
+        self.scorer = scorer or ChapterScorer()
+
+    def _to_artifact(self, content: ChapterContent) -> ChapterArtifact:
+        """把 ChapterContent 转换为评分器所需的 ChapterArtifact（聚合正文与来源 URI）。"""
+        text = "".join(b.text or "" for b in content.blocks)
+        source_uris: list[str] = []
+        for b in content.blocks:
+            source_uris.extend(b.source_uris)
+        return ChapterArtifact(
+            chapter_id=content.chapter_id,
+            text=text,
+            source_uris=source_uris,
+            template_sections_expected=[],
+        )
+
+    def validate_chapter(self, content: ChapterContent, structured_source) -> tuple[bool, EvalReport]:
+        report = self.scorer.score([self._to_artifact(content)], structured_source)
+        passed = content.chapter_id not in report.failed_chapters
+        return passed, report
+
+    def validate_document(self, contents: list[ChapterContent], structured_source) -> list[tuple[bool, EvalReport]]:
+        return [self.validate_chapter(c, structured_source) for c in contents]
diff --git a/tests/test_phase5_validator.py b/tests/test_phase5_validator.py
new file mode 100644
index 0000000..73c7151
--- /dev/null
+++ b/tests/test_phase5_validator.py
@@ -0,0 +1,32 @@
+from genesis.qa.validator import QAValidator
+from genesis.writer.models import ChapterContent, ContentBlock
+
+
+def _chapter(cid, text):
+    return ChapterContent(
+        chapter_id=cid, version=1, title=cid,
+        blocks=[ContentBlock(block_id="1", type="paragraph", text=text)],
+    )
+
+
+def test_validate_chapter_passes_good():
+    v = QAValidator()
+    passed, report = v.validate_chapter(_chapter("a", "充分且规范的说明内容，满足写入规则要求。"), None)
+    assert passed is True
+    assert "a" not in report.failed_chapters
+
+
+def test_validate_chapter_fails_short():
+    v = QAValidator()
+    passed, report = v.validate_chapter(_chapter("b", "x"), None)
+    assert passed is False
+    assert "b" in report.failed_chapters
+
+
+def test_validate_document_aggregates():
+    v = QAValidator()
+    results = v.validate_document(
+        [_chapter("a", "充分且规范的说明内容，满足写入规则要求。"), _chapter("b", "x")], None
+    )
+    assert len(results) == 2
+    assert results[0][0] is True and results[1][0] is False