Abstract: Characteristic of large power generation, small floor area, clean and pollution-free, the wind turbine has become the fastest growing new clean energy. Wind power tower as the basic component of wind turbine, its quality directly affects the safety of the whole unit. At present, there are still some problems to be solved in the detection method of the welding seam of the wind power tower. This paper introduces the research and application of phased array ultrasonic testing method in the welding seam of wind power tower, and its advantages compared with the existing conventional nondestructive testing methods.