Abstract: The impact test for spacecraft is generally required with a magnitude between 1000g-2000g, sometime even more than 3000g. In a high-magnitude impact test for large (>500 kg) products, it is difficult for the pendulum impact test equipment and the drop impact test equipment to meet the test requirements. In order to solve these problems, a pneumatic impact test system is designed for the high-magnitude impact test. The system uses the compressed air as the power source, and the instantaneous release of gas to expand the impact mass block, which is accelerated to impact the resonant plate, so that a spectrum similar to the complex damped sine wave is generated in the resonant plate. The test results show that when the system is unloaded, the impact value is up to 8000g. When the load is 200 kg, the impact value is up to 5000g. The time domain curve is the shock attenuation wave, and the duration is less than 10ms. The method proposed in this paper can serve as a reference and theoretical basis for the design of this kind of impact test systems.