讨论了避免电机轴承电蚀失效的主要防护措施，包括安装接地碳刷疏导轴电流、使用绝缘轴承截断轴电流这两类方式，并对其优缺点分别进行了阐述。针对绝缘轴承，着重分析了Al2O3陶瓷涂层的热喷涂工艺(粉末粒径、喷涂参数等)、涂层结构(表面形貌与微观组织)以及涂层性能(力学性能、摩擦性能、绝缘性能)三者间的关系，介绍了通过掺杂其他金属阳离子氧化物或纳米结构粉末对涂层性能进行改性的方法。在此基础上，对绝缘轴承Al2O3陶瓷涂层制备技术存在的难点进行了分析，总结了存在的主要问题。最后对绝缘轴承Al2O3陶瓷涂层制备技术的发展趋势进行了展望。

This paper discusses the main protective measures to avoid electrical corrosion failure of electromotor bearings, including the installation of grounded carbon brushes to channel the shaft current, and using insulated bearings to cut off the shaft current, and the advantages and disadvantages of them are explained respectively. For insulated bearings, the relationship among the thermal spraying process (powder particle size, spraying parameters) the coating structure (surface morphology and microstructure) and the coating properties of the Al2O3 ceramic coating are analyzed, and the methods of modifying the coating performance by doping other metal cation oxides or nanostructured powders are introduced. On this basis, the difficulties existing in the preparation technology of Al2O3 ceramic coating for insulated bearings are analyzed, and the main problems are summarized. Finally, the development trend of Al2O3 ceramic coating preparation technology for insulated bearings is prospected.