A kind of crash energy absorption structure used by vehicle simulator crash testing equipment based on mechanical energy storage was studied. Dynamic explicit finite element simulation was conducted for steel tube combination structure under different conditions of length, center distance, thickness, and section dimension. Crash energy absorption characteristics of the structure were obtained. After optimization, a reasonable structure was given which can meet current vehicle crash regulation. And the optimized structure can be used in vehicle simulator, which increases the practicability of the testing equipment.