The optimization design parameter model of the base of explosion一proof motor has been estab- lished by using the finite element analysis software Ansys. Structure of the base has been optimized as well as the weight of the base as the objective function, during the optimization process, considering the stress constraints and the displacement constraints that the base suffered, and the integrated displacement and stress before and after optimization were compared with each other. The result shows that the displacement and stress have increased in pcrmitted rare after optimization. The result of optimization reduced greatly weight of the base in the case of the normal, stable operation, thus it could save a lot of raw materials for the mass production and it has important practical signfficance for lower production cost and could creates higher economic benefit.