Abstract: An integrated optimization model based on genetic algorithm and dynamic programming method is proposed to optimize manufacturing process during process planning. Due to the complexity of manufacturing process, this model decomposes the process into two parallel aspects and the optimization is conducted respectively. For the aspect of working procedures, genetic algorithm is improved to optimize their process parameters efficiently, which belongs to the constraint optimal problems that are usually difficult to deal with for genetic algorithm. And for the aspect of routings, dynamic programming method is employed to search the best manufacturing routing. Based on the local optimization by generic algorithm, the whole manufacturing process is optimized by using dynamic programming method. A case study is also presented to demonstrate the feasibility and effectiveness of the model.