Abstract: In the future extraterrestrial celestial detection, the landing, the sampling, the returns and other activities are usually involved. In this paper, the attitude and motion simulation device for space environment simulation tests for the detector return takeoff is studied. A six degree-of-freedom Stewart platform is proposed as the attitude and motion simulation device. The device can simulate the static and dynamic posture adjustment. The layout of the device in the vacuum chamber and the principle of the device are discussed. The device is controlled by an upper computer and lower computers. The motion parameters of the device could be set in the upper computer through software, and then the motion parameters are transferred to the lower computers for control. The device can meet the attitude and motion simulation requirements of the detector test.