Abstract: Aiming at the problems of redundant cross-sections and low material utilization in the design of girder cranes, a multi-objective optimization study was conductbining parametric modeling, finite element simulation, and genetic algorithms. Taking box-section parameters as design variables, an optimization model was established with dual objectives of minimizing mass and controlling deformation constraints of strength and stiffness, and solved using the MATLAB gamultiobj function. After optimization, the total cross-sectional area and mass of the main beam decreased by approxy 10%, while the maximum static stress and mid-span deflection increased slightly but still met the safety limits of the code; the first six natural frequencies remained above 2.0 Hz, eliminating the risk of resonance. The optimized scheme conforms to the basic laws of structural mechanics, ensuring structural safety and reliability while achieving moderate lightweighting, providing a reference for the engineering dgn of girder crane main beams.