Abstract: During the course of docking dynamic test, the contact force is beyond the index. Math model is built to simulate the test process, and the suggestion is given to solve the problem. According to the math simulation results, modified components were assembled to the docking systems. Finally, the results of the math simulation indicate that the force data contains the structure frequency information, and the later modal test for the spacecraft simulators validates the math model, and the suggestion is given that the docking dynamic test data should be filter.