Physics-based animation has always been an issue of computer graphics. A new numerical computing method named Numerical Manifold Method is firstly introduced into the area of computer animation. A general mechanical model is developed by making use of the advantage of numerical manifold method. It is simulated that an elastic object is being unfolded, a ball collapses into a square consisting of several little elastic blocks, and an elastic ball is pulled through rigid running gears. Simulation results show that the mechanical model has the potential advantage on multi-deformable objects simulation and the creation and spread of the joints.