The components of the gun endure acute vibration during its shooting process. If the amplitude of vibration is too high, bodywork's vibration will cause great initial disturbance, make the pill miss the preset target and impact the accuracy of firing. If gun's shooting vibration has been tested, its signal could be processed and analyzed, which can offer valuable reference for the effect of initial disturbance to gun's firing accuracy. The paper designs the testing system for gun's shooting vibration, according to the test state and requirement during gun's shooting. With the problem of noise interference inside the signal, wavelet threshold de-noising is adopted to decrease noise when the principle of heuristic threshold and improved threshold function are used. Then the characteristics in time and frequency domain are enhanced.