Abstract: As one of the main and large-scale components of canned main circulation pump, the weight and size of canned motor possess direct impact on the weight and volume of main circulation pump. Based on mapping crossover genetic algorithm, a self-developed method, the research on the conceptual design optimization of canned motor was carried out with the weight of effective material of the canned motor as the objective of optimization. The results show that the optimal weight of effective material is 9.933% less than the original design proposal, and the optimization effect is obvious. The sensitivity study of the effects of relevant parameters of the geometry size, wires and groove shape on the weight of effective material was also conducted in this paper. Corresponding results can provide reference for engineering design.