The automotive seat frame is a core component to ensure the safety and comfort of the occupants, while its lightweight and structural strength optimization is crucial to the vehicle energy saving and emission reduction as well as the improvement of crash safety. Specifically, finite element models for seat modal frequency test, seatbelt anchorage test, and seat back strength test were firstly developed using a front seat frame as the research object. Then the thickness of the component as a design variable was screened based on mass sensitivity analysis. Next, sample points were collected using the Latin hypercubic sampling method and a moving least squares approximation model was established. Finally, the entropy-weighted Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method is used to evaluate the pareto solution set, and the optimal solution is obtained. The results show that the frame mass of the car seat reduces the deformation of the slide rail, and ensures the safety and comfort of the seat. Therefore, it is proved that the method in this study is effective for the multi-objective optimization of the seat frame.