Abstract: he brazed joint of honeycomb structure was tested by acoustic impedance method. The sample with artificial defects was made according to the standard; the testing signal was obtained based on the principle of acoustic impedance test, and then the manual testing process was determined. The -scan image was obtained by combining the location signal of the probe picked up by the handwriting board and the corresponding testing signal by a C++.NET program, and the image was compared with the ultrasonic C-scan result. It was shown that the test process of acoustic impedance method was easy to obtain, and has a high testing speed. The  10 mm debond in the honeycomb structure can be detected by this method. The location and size of the artificial defects was shown in the acoustic impedance C-scan image, and the resolution met the test requirement.