In view of the problem that the recoil acceleration-time curve can not be regulated easily and the recoil acceleration duration is not enough by the impact and deceleration method. In order to find the influencing factors of the recoil acceleration-time curve, the foamed aluminum block was adopted as the buffer. After simulating the impact and deceleration process based on ANSYS/LY-DYNA program, it is realized that the foamed aluminum block has good buffer quality, and the recoil acceleration duration is longer when the density is the less. The initial impact velocity, thickness of the foamed aluminum block, density of the foamed aluminum block and quality of the momentum exchange mass are all important influencing factors of the recoil acceleration-time curve.