A primary segmented discontinuous linear motor applied to the annular line transportation system is taken as the research object. The merits of the segmented discontinuous primary structure include cost savings, reduced losses, and a more flexible motor system, but this structure results in a large end force on the mover switching between segments , which results in large thrust fluctuations during motor operation. To solve this problem, an optimization method combining the secondary auxiliary pole and primary end teeth is proposed. The detent force of the motor during no-load operation is emulated and analyzed, and the detent force on the mover in the two cases of primary coupling and switching between segments are compared. Firstly, the main structural parameters of the motor are optimized, the multi-objective response surface model is established by combining the response surface method. Secondly, optimization is performed by genetic algorithm, and the detent forces before and after optimization are compared by simulation; Finally, a test verification based on the prototype is carried out, and the results show that the motor model with an auxiliary structure can effectively suppress the detent force and thrust fluctuation.