diff --git a/src/lib/hugoParser.ts b/src/lib/hugoParser.ts
index 0ccaba0..eda08d0 100644
--- a/src/lib/hugoParser.ts
+++ b/src/lib/hugoParser.ts
@@ -10,6 +10,8 @@ export interface HugoPostData {
 	updated_at: string;
 	categories: string[];
 	tags: string[];
+	series: string[];
+	series_weight: number | null;
 }
 
 /**
@@ -41,6 +43,12 @@ function parseArrayField(val: unknown): string[] {
 	return [];
 }
 
+function parseIntegerField(val: unknown): number | null {
+	if (val === null || val === undefined || val === '') return null;
+	const parsed = typeof val === 'number' ? val : Number(String(val).trim());
+	return Number.isInteger(parsed) ? parsed : null;
+}
+
 /**
  * 去掉文件名结尾的格式拓展名，提供纯文件名基础
  */
@@ -120,6 +128,8 @@ export function parseHugoMarkdown(rawContent: string, fileName = ''): HugoPostDa
 		published_at,
 		updated_at,
 		categories: parseArrayField(meta.categories || meta.category),
-		tags: parseArrayField(meta.tags || meta.tag)
+		tags: parseArrayField(meta.tags || meta.tag),
+		series: parseArrayField(meta.series),
+		series_weight: parseIntegerField(meta.series_weight)
 	};
 }
diff --git a/src/lib/server/series.ts b/src/lib/server/series.ts
new file mode 100644
index 0000000..62a87fe
--- /dev/null
+++ b/src/lib/server/series.ts
@@ -0,0 +1,48 @@
+export class SeriesValidationError extends Error {}
+
+export function parseSeriesId(value: FormDataEntryValue | null): number | null {
+	if (value === null || value.toString().trim() === '') return null;
+
+	const id = Number(value);
+	if (!Number.isInteger(id) || id <= 0) {
+		throw new SeriesValidationError('系列选择无效');
+	}
+
+	return id;
+}
+
+export function parseSeriesWeight(value: FormDataEntryValue | null): number | null {
+	if (value === null || value.toString().trim() === '') return null;
+
+	const weight = Number(value);
+	if (!Number.isInteger(weight)) {
+		throw new SeriesValidationError('系列顺序必须是整数');
+	}
+
+	return weight;
+}
+
+export async function resolveSeriesWeight(
+	db: D1Database,
+	seriesId: number | null,
+	requestedWeight: number | null,
+	excludePostId?: string
+): Promise<number | null> {
+	if (seriesId === null) return null;
+
+	const series = await db.prepare('SELECT id FROM series WHERE id = ?').bind(seriesId).first();
+	if (!series) {
+		throw new SeriesValidationError('所选系列不存在');
+	}
+
+	if (requestedWeight !== null) return requestedWeight;
+
+	const query = excludePostId
+		? 'SELECT COALESCE(MAX(series_weight), 0) + 1 AS next_weight FROM posts WHERE series_id = ? AND id != ?'
+		: 'SELECT COALESCE(MAX(series_weight), 0) + 1 AS next_weight FROM posts WHERE series_id = ?';
+	const result = excludePostId
+		? await db.prepare(query).bind(seriesId, excludePostId).first<{ next_weight: number }>()
+		: await db.prepare(query).bind(seriesId).first<{ next_weight: number }>();
+
+	return result?.next_weight ?? 1;
+}