Abstract: In response to the requirements for launch of the Mars ascent vehicle (MAV) during the Mars sample return mission, a cold ejection device with controllable pitch angle was designed. The cold ejection device has the characteristics of light weight, simple structure and high reliability. It can realize ejection and control the pitch angle of the MAV at the highest point of ejection. Firstly, by analyzing the motion of the ejection device and the MAV, the theoretical minimum force required for ejection was obtained. Then, the finite element model of the ejection device and the MAV was established in ABAQUS to verify the feasibility of the ejection device. Considering the complex environment on the surface of Mars, four extreme ejection conditions were simulated, including pitch ±30°, roll +30° plus pitch ±30°. The results show that under all conditions, the ejection device can achieve a distance greater than 4 meters from the highest point of the MAV ejection to the launch platform and a pitch angle greater than +15° at the highest point of the MAV ejection. Finally, based on theoretical analysis and simulation, it shows that the effect of Martian atmospheric drag on the ejection process is negligible.