In recent years, the long-distance pipeline running safety is the focus of study.On the basis of studying the principles and characteristics of PAUT detection and RT detection, the advantages and disadvantages of PAUT detection and RT detection and the evaluation principles are compared according to the current standards and norms.By taking a case study of a long-distance pipeline project as the research sample, this paper analyses the defects-checking contrast and mechanics between PAUT and RT detection.Through comparison, it is proved that PAUT detection has relatively high detection ability for defects.On this basis, verification is carried out to confirm the validity and accuracy of PAUT detection.Finally, according to the existing problems of non-destructive testing of long-distance pipelines, suggestions are put forward to improve the inspection management of long-distance pipeline projects in the future.