本文讨论了弹性碰撞成立的条件,通过对一个较简单的弹性体碰撞过程的计算.得出,弹性碰撞除了要求碰撞过程中相互作用的内力完全是由于形变引起的弹性力(保守力)外,还要求碰撞物体刚度大(即变形小)、几何尺寸小,从而碰撞时间短,碰撞作用瞬间传到整个物体,宏观物体的碰撞才可近似地看作是弹性碰撞. In this paper, the conditions for the establishment of elastic collision are discussed, and the calculation of the collision process of a simple elastic body is given. It is found that the elastic collision requires not only the elastic force (conservative force) due to deformation but also the internal force of interaction during the collision, It is also required that the collision object has a large rigidity (ie, a small deformation) and a small geometric dimension, so that the collision time is short and the collision moment is transmitted to the entire object momentarily. The collision of the macro objects can be approximated as an elastic collision.