In order to ensure the improvement of aviation maintenance quality, ensure the quality control of in-service aircraft maintenance process, and provide theoretical basis for the repair process, non-destructive testing, as a crucial testing technology in the field of aircraft maintenance, must be fully researched and applied. In this paper, the non-destructive testing technology for in-service aircraft components is studied, and its importance in aircraft regular inspection and maintenance, application advantages and limitations and application scope are discussed. Based on the application of non-destructive testing of actual flight damaged components as the research background, according to the cases provided by the project, combined with the actual damage situation, comprehensive analysis of the detection characteristics and detection technology, through the practical application of ultrasonic pulse reflection method and fluorescence penetration detection of the spray can method, to achieve the detection and identification of the defects of the damaged structural parts; At the same time, it discusses the future application trend of in-situ non-destructive testing for aircraft maintenance and the development of new structures and new materials under a variety of new non-destructive testing technologies and new methods, so as to better realize the comprehensive evaluation of in-service parts damage, and provide valuable reference for future aircraft maintenance application and non-destructive testing technology program selection, which is conducive to continuous improvement in the follow-up research practice.