Abstract: In order to study the feasibility of the in-service tap test technology for radome, the principle of the tap testing was analyzed, and the instrument tap and hammer tap were applied to test the radome specimen and the radome parts in service. The results show that the debond defect, whose nominal size is larger than 25 mm, can be found using the two kinds of the tap test methods. It satisfies the quality request of the radome being test in service. It is the same to the instrument tap and the hammer tap in the ability of finding defect. And there is diffidence between the two tap methods in the operation and resisting the environment noise. The study is useful for testing radome in service.