A 3D electrochemical-thermal coupled finite element analysis (FEA) model is established on COMSOL Multiphysics® software for 40 A h ternary prismatic lithium-ion batteries. The input parameters in this model are current C-rate C, battery thickness Th bat , initial battery ambient temperature T int , positive porous electrode thickness Th pos , positive particle diameter D pos , positive electrode solid phase volume fraction ε 1,pos , respectively. Response surface methodology (RSM) with variance analysis (ANOVA) and parametric scanning is employed for simulating and optimizing the data obtained from the Box-Behnken experimental design based on this model. After that, the optimized parameters are verified to evaluate the reliability of the model on heat generation. The results of response surface optimization show that the optimized model error is less than 0.76% and the final temperature drops is 0.55 K. This novel model is reliable and accurate, which is helpful to improving the electrochemical and thermal performance of the battery. Also, it can provide optimized and feasible solutions for other similar kind of batteries, which offer the reference for design and optimization of the battery management system.