Poly(vinyl alcohol) (PVA) which are used for the transparent, recyclable, and environmental-friendly food high-barrier flexible packaging materials due to their good transparency and film-forming properties, as well as excellent oxygen and organic solvent barrier properties. However, the development of PVA coating is restricted by its poor humidity sensitivity and the lack of water vapor barrier properties. For these reasons, there are currently two main methods to solve the application problems of PVA coating: one method is to chemically cross-link PVA which can undergo the chemical reactions such as esterification, etherification and acetalization similar to other polyols containing secondary alcohols; the other method is to prepare PVA-nanomaterial composite coating, wherein the PVA and nano-layered materials such as montmorillonite (MMT) and graphene oxide (GO) have been made great progress. For this reason, the barrier properties of PVA and its influencing factors, chemically cross-linked PVA coatings and PVA-nanocomposite coatings were introduced, the problems faced by modified PVA coatings and prospects were analyzed, and their future research directions were prospected.