Abstract: In this paper, microwave nondestructive testing technology of industrial metal pipe surface defects was experimental researched which included microwave NDT of inner and outer surface defects of the metal pipe. The results showed that using microwave NDT technology could realize non-contact detection of outer surface of the pipe. In addition, this technology also could achieve fast positioning and determination of pipe inner surface defects which could greatly improve the efficiency of pipe inspection. The research provided an important basis for safety assessment of industrial metal pipe.