With the increase of service time, the maintenance quality of old helicopters has brought more challenges. This article introduces the application of aviation non-destructive testing in the field of aviation maintenance and the characteristics and maintenance status of old helicopters, We explores and determines the key parts and key components of non-destructive testing for old helicopters based on the structural characteristics and usage of helicopters, elaborates on the specific application methods for testing key parts of helicopters based on the characteristics of different non-destructive testing technologies, and studies the timing of using non-destructive testing technology in the maintenance practice of old helicopters. Finally, we have made prospects for the application of non-destructive testing technology in the maintenance of old helicopters.