A great influence will be exerted on the machining efficiency by the optimization degree of machining paths for group holes. An optimized processing path, based on a research of TPS mathematical models, can be achieved by the application of an improved hybrid genetic algorithm to the solution of the optimization of holes machining paths. A comparison between the classical genetic algorithm, the ant colony algorithm and an improved hybrid genetic algorithm shows that the proposed optimized method helps to improve the machining efficiency by greatly shortening the machining time.