Abstract: To evaluate the residual load-bearing capacity of 6063-T5 aluminum alloy structures after fire exposure, model tests and numerical simulations were conducted on rectangular hollow sections(RHS) and square hollow sections(SHS) subjected to localized transverse loading, considering variables such as geometric dimensions, exposure temperatures and loading board lengths. The stress-strain curves, load-displacement curves, and failure modes of RHS and SHS after high-temperature exposure were obtained. The results indicate that the 6063-T5 aluminum alloy subjected to high temperatures exhibits a significant decrease in strength and increased ductility. After the validation of the numerical analysis method, a parameter analysis was performed comprising 480 numerical models. Based on the combined experimental and numerical results, the applicability of the design methods according to Eurocode 9(EC9) was evaluated. The findings reveal that EC9 design methods are not suitable for predicting the residual local transverse load-bearing capacity of RHS and SHS made of 6063-T5 aluminum alloy after exposure to different high temperatures. Therefore, high-temperature exposure affects the mechanical properties of 6063-T5 aluminum alloy, thereby reducing the accuracy of current design methods.