The advantage of entering a cross-reference as a field is that you do not have to adjust the references manually every time you change the document. Just update the fields with F9 and the references in the document are updated too.
若您将一个交叉引用作为字段插入，则您在修改文档时不必总是手动调整引用。只需利用 F9 键更新字段，文档中的引用也同时被更新。