In this paper, we present a voxel-based collision detection method for clothed human animation. We speed up the performance of the voxel-based method by choosing an appropriate voxel size and using a fast voxelization approach. Based on the voxel method, we propose a self-collision detection method and a simplified collision detection method. First, the efficiency of self-collision detection is improved by taking advantages of the curvature and multi-layer methods. Second, the efficiency of cloth/human collision detection is improved by introducing auxiliary line segments. Some heuristics are provided to further increase the efficiency of collision detection. Experimental results demonstrate that our method is efficient for clothed human animation.