从纳米多层涂层和纳米复合涂层两个角度总结了PVD纳米涂层的强化机制和涂层设计准则，提出了现有的涂层强化机制及涂层设计准则主要存在涂层强化机制适用性不足和理论性问题缺乏实验手段论证两个问题，并合理分析了问题存在的原因。从纳米多层涂层和纳米复合涂层两个角度，综述了PVD纳米涂层致硬机理的国内外研究现状。研究现状表明，涂层强化机制和一些涂层表征实验在涂层致硬机理研究中扮演着重要的角色，研究者们根据涂层强化机制和必要的实验手段对涂层的致硬机理进行了分析。但是涂层强化机制并非涂层致硬机理研究中必不可少的工具，既存在用一种或多种涂层强化机制解释涂层致硬机理的情况，又存在未使用涂层强化机制去解释涂层致硬机理的情况。针对这种现象，分析了其存在的内因和外因。外因为涂层材料组合方式和实验研究变量不同；内因为涂层强化机制及设计准则不完善。最后结合PVD纳米涂层致硬机理研究现状存在的问题，本着完善涂层强化机制和设计准则的目的，对未来研究方向进行了展望。

The work aims to summarize the strengthening mechanism and design criteria of PVD nano-coating from the perspectives of nano-multilayer coating and nano-composite coating, to propose the two main issues as poor applicability of coating strengthening mechanism and lack of experimental means to prove theoretical problems existing in the current coating strengthening mechanism and coating design criteria and analyze the causes of the problems reasonably. The research status of the hardening mechanism of PVD nano-coating at home and abroad was reviewed from the perspectives of nano-multilayer coating and nano-composite coating. The research revealed that the strengthening mechanism and some coating characterization experiments played significant roles in the study of coating hardening mechanism. The researchers analyzed the hardening mechanism of the coating according to the strengthening mechanism and necessary test methods. However, the strengthening mechanism of coating was not an essential tool for the study of the hardening mechanism of coating. There was not only one or more coating strengthening mechanisms to illustrate the coating hardening mechanism, but also no coating strengthening mechanism to explain the coating hardening mechanism. In view of this phenomenon, the internal and external factors were analyzed. The external factor was that the combination of coating materials and experimental variables were different; and the internal factor was that the coating strengthening mechanism and design criteria were not perfect. Finally, combined with the existing issues in the research on the hardening mechanism of PVD nano-coating, the future research direction was proposed based on the purpose of improving coating strengthening mechanism and design criteria.