The new generation of lithium aluminosilicate glass has gradually become the mainstream structural material for aerospace transparencies. Due to its high elastic modulus and excellent ion exchange capability, lithium aluminosilicate glass exhibits superior mechanical properties after chemical reinforcement treatment, well meeting the requirements of lightweight and high strength for aerospace transparencies. This paper aims to explore the effect of chemical reinforcement processes on impact resistance of 3~6 mm thick lithium aluminosilicate glass. Samples were prepared under different reinforcement conditions, and the effect of stress distribution on impact resistance was analyzed through ball-drop impact testing and theoretical calculations. It is found that for thick lithium aluminosilicate glass, as the depth of the stress layer increases, the growth of central stress is slower. Moreover, thicker lithium aluminosilicate glass exhibits a slower growth rate of central stress, and its impact resistance improves with the increase in the depth of the stress layer, which differs from the pattern observed in thin lithium aluminosilicate glass.