The paper aims to obtain the optimal scheme for reducing the mass while improving the working and mechanical properties of the push arm by optimizing the structural dimensions of the push arm. Taking the mass of the push arm as the optimization goal, the pressure of the push arm as the constraint condition, and the structure size of the push arm as the optimization design parameter, the optimized mathematical model was established. The multi-objective driven optimization tool of Workbench was applied to optimize the structural size of the push arm in combination with the theory of multi-objective genetic algorithm. Through optimization analysis, the results showed that the equivalent stress maximum value of the optimized model decreased by 23.08% and the total mass of the structure decreased by 7.42%. Through the research and analysis of different structure sizes under their constraints, better working and mechanical properties of the push arm are achieved under the optimal structure size. The total mass of the components is smaller. It provides ideas and reference for the structural optimization design of the box adhesive machine in the future.