Abstract:The ultrasonic longitudinal wave method is an ideal method for in-situ bolt detection. In order to optimize the ultrasonic testing parameters and improve the reliability of in-service aviation bolt damage detection, the typical aviation bolts are selected as test specimens in this paper, the simulated crack defects were made at different positions, and various parameters were used to test the bolts. The influences of the wave forms and different parameters on the test results were analyzed, lower frequency and smaller chip size are better. At the same time, this paper analyzes the interference of deformation wave, and puts forward effective measures and countermeasures to improve the reliability of defect detection and the accuracy of defect wave discrimination.