Abstract: A radar mainly detects the three-dimension structure of subsurface targets. The airborne flight method is an effective way to verify the technical index and solve the key technology. In this paper the structure design，the mechanics design and analysis of the airborne flight payload are carried out according to the detection mission requirement and the airborne vibration environment. The airborne flight test shows that the prototype meets the requirements of the airborne flight environment and the system works normally, which verifies the reasonability of the structure design.