Abstract: In order to verify the influence of the surface slope and the gravity environment on the performance of the lunar probe and the related equipment, a device for simulating the inclined posture of probe is designed. The device is a double crank rocker mechanism, including the stepper motor, the spiral elevator, the rotating platform and the frame. In the environment of high vacuum and ultralow temperature, and with the requirements of large size, over loading and high precision, the related difficulties in the course of designing are discussed. The mechanism is successfully applied to the Chang'e-3 and Chang'e-5 thermal vacuum tests, with all requirements satisfied.