Abstract: The single layer reticulated shell is a kind of imperfection sensitive structure. The initial geometric imperfections have a significant impact on the section optimization results of the shell. This paper studies the relationship among the rod section optimization value, the initial geometric imperfection distribution, the ultimate bearing capacity and the member buckling failure law of the structure. It is indicated that the most unfavorable stress appears early and keeps growing until the buckling failure in the place where the initial geometric imperfection is larger on the structure after the section optimization design. The section optimization results are directly related to the initial geometric imperfection distributions, which means that increasing the cross-section of the rod where the initial geometric imperfection is larger would effectively enhance the ultimate stability bearing capacity. Due to the random distribution of the initial geometric imperfection, the stable bearing capacity of the reticulated shell after the section optimization design must be checked under different defect distributions to ensure safety.