In the maglev pipe rail transportation system,adopting the same plane installation scheme of suspended electromagnets and linear induction motors(LIM)can effectively reduce the shield tunneling area and lower construction costs;At the same time,LIM normal force can provide auxiliary suspension force,improving the overall energy efficiency of the system.A response surface methodology based integrated LIM optimization design method is proposed to address the issues of large modeling errors and complex optimization in the collaborative optimization of traction and normal forces.Firstly,establish the design goals for traction and normal force,and complete the initial design of the motor.Secondly,combining Box Behnken experimental design method and analysis of variance method,analyze the influence of motor parameters on traction force and normal force,and determine the sensitive parameter set.Once again, a second-order surrogate model for sensitive parameters was established using response surface methodology and passed the model fitting test.Under constraints such as machining accuracy and motor saturation,a second-generation non dominated sorting genetic algorithm is used to perform multi-objective optimization on the surrogate model.Finally,use Maxwell software to perform time-step finite element simulation on the motor before and after optimization.The results showed that under the working conditions of power frequency and rated current of 15 A,the initial traction and normal force of the motor were 305.9 and-60.5 N,respectively,and optimized to 309.4 and -309.3 N,respectively.The performance indicators were significantly improved after optimization,with design errors of 3.13%and 3.10%, respectively.This indicates that the collaborative optimization design method is practical and effective.