When aluminum alloy tube have defects, they may be damaged by lateral impact in practical applications. Based on the general finite element analysis software, the dynamic analysis and performance research on lateral impact of aluminum alloy tube with and without defects with different diameter to thickness ratios and impact velocities were conducted in this paper. The results show that aluminum alloy tube with defects have weak impact resistance and are prone to local damage. Reducing the diameter to thickness ratio of aluminum alloy tube can improve the impact resistance of the structure; when the impact speed is the same, due to large tensile deformation at the midspan defect, energy is locally absorbed by the defect, and the maximum midspan displacement of the tube with defects is smaller than that of the tube without defects; The larger the impact velocity is, the tube with and without defect reaches the mid-span displacement peak at the same time, but the displacement of the tube with defect enters the stable stage faster.