The air suction engine containing sand and dust will inevitably collide with the blade and the inner and outer casing,which will affect the flight safety of the aircraft.By using explicit dynamic analysis finite element method,the rebound model of sand and dust impacting on the wall with different incident angles,incident velocities, particle size and rotating velocities was established.The rebound characteristics of sand and dust impacting on stainless steel and aluminium alloy surfaces under different conditions were studied,which provided data support for predicting the trajectory of sand and dust in particle separator.The results show that the rebound velocity increases with the increase of the incident velocity of sand and dust,and the velocity recovery coefficient keeps stable basically;under the same incident condition,the influence of aluminum alloy on the velocity recovery coefficient of sand and dust is smaller than that of stainless steel;the impact of rotational velocity and particle size of sand and dust on the impact rebound characteristics is weak and can be neglected.The sand and dust rebound angle depends only on the collision attitude and incidence angle of sand and dust.