The lightweight design has been recognized as a typical effective method for energy saving and emission reduction during parts manufacturing. Therefore, modeling analysis and lightweight design based on the ANSYS workbench for the brake camshaft are proposed. Firstly, the brake camshaft model is imported into the workbench to simulate the static analysis. The stress, deformation, and fatigue life of the brake camshaft are obtained by mesh dividing, boundary conditions defining and loading, and the modal of the brake camshaft is simulated to obtain the modal natural frequency. Then, on the basis of the lightweight design and safety performance of the brake camshaft, the structure of the brake camshaft is optimized, the model has compared again, and the lightweight design scheme can be obtained. The results show that the weight of a brake camshaft decreases by 1.4797 kg, and the cost decreases by 20.8% after lightweight. This method can optimize the structure, save materials, reduce production costs, and shorten the production cycle. This lightweight design method has important reference and practical significance for the production design of the brake camshaft and similar products.