The working environment temperature of the submersible linear motor changes with the depth of the stratum, and the temperature difference between the end and the middle of the motor secondary is large. In order to reduce the influence of temperature variation on motor thrust, increase motor thrust and reduce thrust ripple, the structural parameters of the motor are optimized. The thrust difference under different temperatures is used to measure the influence of temperature variation on motor thrust. The electromagnetic model of the motor is established by using the finite element analysis software Magnet, and the effects of various parameters on the motor thrust, thrust ripple and thrust difference at different temperatures are analyzed, and the numerical ranges of the optimized parameters are determined. Then, the mathematical models of thrust and thrust ripple at 100 ℃ and 220 ℃ are constructed respectively by response surface method. Taking the absolute value of the difference of thrust functions at 100 ℃ and 220 ℃ as the mathematical model of thrust difference, the optimal parameter combination of motor is obtained by multi-objective genetic algorithm. Finally, the finite element simulation analysis of the optimized motor verifies the effectiveness of the optimization scheme.