为了提高汽车车顶前横梁的强度、刚度、轻量化水平，实现材料和结构等方面的平衡，构建碳纤维复合材料前横梁的设计与优化方法，通过提出改进的粒子群优化-细菌觅食优化（particle swarm optimization-bacterial foraging optimization, PSO-BFO）混合算法和铺层多层次优化方法，设计了碳纤维复合材料车顶前横梁。建立白车身有限元模型，并实验验证了模型的准确性，获得优化前的前横梁有限元模型。模拟前横梁在顶压、三点弯曲和压缩工况下的性能，确定铺层优化的边界条件；对T700/WP-R2300材料进行性能测试，为铺层优化提供材料参数；通过自由尺寸优化、尺寸优化确定了碳纤复材前横梁的铺块形状、厚度，结合PSO-BFO混合优化算法优化了铺层顺序。优化后前横梁减重45.47%，顶压、三点弯曲和压缩工况下位移分别降低43.64%、29.58%和28.61%，应力分别降低85%、79.44%和75.03%，验证了多层次优化方法的有效性。

To improve the strength, stiffness, and lightweight performance of the automotive roof front crossbeam, achieve a balance in materials and structure, and develop a design and optimization method for the carbon fiber composite front crossbeam, an improved particle swarm optimization-bacterial foraging optimization (PSO-BFO) hybrid algorithm and a multi-level layup optimization method were proposed. The carbon fiber composite roof front crossbeam was then designed using these approaches. A finite element model of the body-in-white was established and experimentally validated for accuracy, resulting in the finite element model of the front crossbeam before optimization. The performance of the front crossbeam under top compression, three-point bending, and compression conditions was simulated to determine the boundary conditions for layup optimization. Performance testing of the T700/WP-R2300 material was conducted to provide material parameters for the layup optimization. Through free-size optimization and size optimization, the shape and thickness of the carbon fiber composite front crossbeam layup were determined, and the layup sequence was optimized using the PSO-BFO hybrid optimization algorithm. After optimization, the weight of the front crossbeam is reduced by 45.47%, and the displacements under top compression, three-point bending, and compression conditions decrease by 43.64%, 29.58%, and 28.61%, respectively. The stresses are reduced by 85%, 79.44%, and 75.03%, respectively, validating the effectiveness of the multi-level optimization method.