In view of the problem of the high design cost of N90 rack columns in shuttle-styled medium-sized stereoscopic warehouses, an optimization has been achieved for the cross-sections. Firstly, the column sections are parameterized with 9 independent parameters representing the entire section. Subsequently, the composite method is adopted to consider minimizing the cross-sectional area while reducing the length-to-slender ratio. Combined with ANSYS analysis software, a research is conducted on the influence of 8 variable parameters on the performance of the column, thus obtaining the trend of the influence of each parameter on the shelf. Based on an optimization of the cross-sectional parameters of the shelf columns through the above steps, the analysis results show that the optimized column cross-sectional area has decreased by 3.1%, with the length-to-slender ratio decreasing by 2.9%. The fatigue life has increased by 16.77%, while the safety factor has increased by 4.32%, indicating that the optimized shelf columns are even better in performance compared with those before optimization.