diff --git a/src/app/record-detail.test.ts b/src/app/record-detail.test.ts
new file mode 100644
index 0000000..3dd8383
--- /dev/null
+++ b/src/app/record-detail.test.ts
@@ -0,0 +1,41 @@
+import { describe, it, expect } from "vitest";
+import { pickRecordTitle, formatCellValue } from "./record-detail";
+import type { DataRow } from "./table-filters";
+
+describe("pickRecordTitle", () => {
+  it("prefers 生产订单号", () => {
+    const row: DataRow = { 生产订单号: "PO-1", 总排号: "X", ID: 1 };
+    expect(pickRecordTitle(row)).toBe("PO-1");
+  });
+  it("falls back to 总排号 when 生产订单号 blank", () => {
+    const row: DataRow = { 生产订单号: "  ", 总排号: "X-9", ID: 1 };
+    expect(pickRecordTitle(row)).toBe("X-9");
+  });
+  it("falls back to ID when earlier are null/empty", () => {
+    const row: DataRow = { 生产订单号: null, 总排号: "", ID: 42 };
+    expect(pickRecordTitle(row)).toBe("42");
+  });
+  it("returns （未命名） when all blank", () => {
+    const row: DataRow = { 生产订单号: null, 总排号: null, ID: null };
+    expect(pickRecordTitle(row)).toBe("（未命名）");
+  });
+});
+
+describe("formatCellValue", () => {
+  it("null -> em dash", () => {
+    expect(formatCellValue(null)).toBe("—");
+  });
+  it("empty / whitespace -> em dash", () => {
+    expect(formatCellValue("")).toBe("—");
+    expect(formatCellValue("   ")).toBe("—");
+  });
+  it("0 is NOT blank", () => {
+    expect(formatCellValue(0)).toBe("0");
+  });
+  it("number stringified", () => {
+    expect(formatCellValue(123)).toBe("123");
+  });
+  it("text preserved", () => {
+    expect(formatCellValue("量程0-1.6MPa")).toBe("量程0-1.6MPa");
+  });
+});
diff --git a/src/app/record-detail.ts b/src/app/record-detail.ts
new file mode 100644
index 0000000..e7ccb3a
--- /dev/null
+++ b/src/app/record-detail.ts
@@ -0,0 +1,26 @@
+import type { DataRow } from "./table-filters";
+
+/**
+ * 取记录的友好标识（用于详情 Modal 标题）。
+ * 优先级：生产订单号 > 总排号 > ID > （未命名）。
+ */
+export function pickRecordTitle(record: DataRow): string {
+  for (const key of ["生产订单号", "总排号", "ID"]) {
+    const v = record[key];
+    if (v !== null && v !== undefined && String(v).trim() !== "") {
+      return String(v);
+    }
+  }
+  return "（未命名）";
+}
+
+/**
+ * 格式化单元格值用于详情 Modal 完整展示。
+ * null / 空串 / 纯空白 -> "—"；其余 String(value)。0 视为非空（与 isBlank 一致）。
+ */
+export function formatCellValue(value: string | number | null): string {
+  if (value === null || value === undefined) return "—";
+  const s = String(value);
+  if (s.trim() === "") return "—";
+  return s;
+}