Optimal path set selection problem is a crucial issue in structural testing. The zero-one optimal path set selection method is a generalized method that can be applied to all coverage criteria. The only drawback to this method is that for a large program the computation may take ten or more hours because the computation is exponentially proportional to the number of candidate paths and proportional to the number of components to be covered. To alleviate the drawback, this paper enhances the method by (1) defining five reduction rules, and (2) reusing previously selected path set(s) to reduce both the number of candidate paths and the number of components to be covered. Since both the number of candidate paths and the number of components to be covered are reduced, the computation time can be greatly reduced.