In order to present a reference for docking experiments of aerocraft on the ground, also to validate design and docking movement, an impact simulation should be adopted. For that, the customized uniform B-splines are utilized to model the contours of docking locks on planar moving. With this model, the colliding process of rigid-bodies, the unilateral constraint problems of contact and numerical methods of normal force are analyzed. In this paper, a real-time optimization algorithm for deciding contact points based on geometric engine is presented. By means of impact method, simulation results are illustrated including contact forces, kinetic energy and momentum of slave lock during docking. The dynamic modeling with contact-impact is implemented by simulation software DAMS, also the stable numerical integration result and reasonable data are obtained.