Abstract: This paper put forward a detection algorithm based on the shortest distance calculation．The algorithm uses convex polyhedron three dimensional space vertex coordinates of convex hull to present convex polyhedron,and the distance between the convex objects comes down to a non-linear programming problem with a restricted condition．Using mixed artificial fish swarm algorithm solves the problem.In the optimization process,using artificial fish swarm algorithm can quickly find the global extremal neighborhood,and in the late process using pattern search method can accurately find the global extremal．Experiments show that no matter in speed or in accuracy,mixed artificial fish swarm algorithm has more obvious advantage than penalty function method and genetic algorithm.

Key words: Convex polyhedron,Collision detection,Nonlinear programming,Mixed artificial fish swarm algorithm