In order to achieve the all objects collision detection of robot fish 2D simulation platform completed, we propose a collision detection algorithm based on discrete. The algorithm taking 2D simulation platform as base, combined with bounding box tree, use computer graphics put up accurately models to every simulation object; and put forwards different collision detection algorithms adapt to objects use separation axis theory, Voronoi Region concepts in graphics, the output test results quickly and accurately. At the same time using motion interpolation, reducing the step size and type intermediate movement mode to achieve simulation continuous collision detection, further improved collision detection accuracy. Experimental results show that the method can achieved simulating continuous collision detection, has high efficiency, precise features.