The structure and the bench test process of a kind of low-shock separation device were introduced.According to the law of conservation of energy and aerodynamics principle,a mathematical model was established.The influence of the support angle on the air-driven separation process was simulated.The simulation results show that the change of upper support angle has little influence on the separation time and peak pressure,while the influence on the separation time and peak pressure induced by the change of lower support angle is obvious.Reliable separation process can be guaranteed by increasing the upper support angle and decreasing the lower support angle.The simulation results are useful for the separation device design and optimization.