In this paper, the grid structure parameters of complex rotary body are optimized, with the maximum load-mass ratio as the optimization objective and the geometric parameters and number of ribs as the design variables, the evaluation index of load bearing efficiency of the model structure was determined, and the single factor analysis was carried out by using the buckling analysis of ABAQUS. The number of longitudinal ribs, width of longitudinal ribs and height of longitudinal ribs have significant effects on the model’s bearing efficiency. The number and width of ring ribs have a low influence on the model’s bearing efficiency. The factor range for orthogonal test is obtained by analyzing actual manufacturing conditions. The orthogonal table L₁₆(4⁵) is designed by using the principle of orthogonality in mathematics. An orthogonal test scheme suitable for complex grid structure is designed. Through numerical simulation, 16 groups of test results were obtained, and the test results were analyzed by range analysis. It is found that the order of influence degree of each factor on the target value is: Longitudinal rib width>rib height>number of longitudinal rib>number of ring rib>ring rib width, and the optimal parameter combination is obtained. Finally, the optimal parameter combination is verified by experiment, and the difference between the theoretical value and the actual value of the maximum load of the rotary body using the optimal parameter combination is found, and the reason of the difference is analyzed.