The outstanding performance of welding technology is the development of welding process from mechanization to automation, intellectualization and informationization. The application of intelligent welding robot is an important symbol of highly automated welding process. Welding robot breaks through the traditional way of welding automation, making it possible for small batch automatic production. Most of welding robots are fixed arm robots, and have two kinds of teaching and intelligence. Teaching robot: through teaching, memorizing welding trajectory and welding parameters, and strictly follow the teaching procedures to complete the welding of products. With only one instruction, the robot can accurately reproduce every step of teaching. This kind of welding robot is widely used. It is suitable for mass production. It is used in the fixed position of pipeline. Its function is mainly teaching and reproducing, and the strain ability of environmental change is poor. There is no room for small scale production of large structures at construction sites. Intelligent robot: it can automatically determine the starting point, the space trajectory and the related parameters according to the simple control instruction, and can automatically track the weld track, adjust the torch attitude, adjust the welding parameters and control the welding quality according to the actual situation. This is the most advanced welding robot. It has the characteristics of dexterity, light and easy to move. It can adapt to the welding tasks of different structures and different locations. It is seldom used at present and is still in the stage of research and development.