Abstract: With the development of China's aerospace field, the traditional manual TIG welding is widely used, but limited by the low welding efficiency and the shortcomings of excessive heat input, which can not meet the quality requirements of aerospace products. Friction plug welding is commonly used in welding defect repair of special field equipment due to the advantages of fast welding speed, wide range of environment, one-time molding and simple process. The basic principle, process, mechanical properties and the current status of Chinese and foreign research of plug welding were mainly summarized, and the technical characteristics, process methods and welding equipment were introduced in detail.