In order to achieve the effect of vehicle lightweight, based on the steel anti-collision beam of a light passenger car, the structure optimization design of the anti-collision beam made of carbon fiber was carried out ac? cording to the low-speed collision standard. Firstly, the cross-section parameters of the anti-collision beam are deter? mined by the full factor test. Considering the material discontinuity caused by different thicknesses of each area, the ply principle based on ply compatibility is proposed, and the thickness space of the anti-collision beam and the corre? sponding ply sequence are determined. In order to optimize the thickness of the anti-collision beam, the multiobjective particle swarm optimization algorithm based on the kriging model is adopted. Based on the traditional par? ticle swarm optimization algorithm, the multi-objective adding point strategy is introduced, which can effectively solve the repeated test design problem caused by the insufficient accuracy of the approximate model, and improve the optimization efficiency. The simulation and sled test of the optimized anti-collision beam show that the low-speed im? pact performance of the carbon fiber anti-collision beam meets the requirements.