In this paper, the influence of control points on vibration results in random vibration test for radar servo system is studied through simulation and destructive experiment. Results show that if the control points are not selected properly, resonance is easy to occur, which makes the response of structure out of tolerance as well as leads to strength failure of the structure. According to the response results of pre-vibration test, properly control points can be selected for the actual vibration test. The result has important reference for reasonable selection of control points in vibration test.