For the pure electric vehicle rear crashworthiness requirements,this paper combined structural topology optimization with orthogonal design. Referenced a domestic pure electric car,by establishing vehicle tail’s topology optimization model,finite element model,size optimization model and for achieving optimal vehicle acceleration and energy absorption of car rear crumple zones under crash safety regulations,optimized the design of pure electric car tail. Eventually get a reasonable optimized configuration and realize the pure electric vehicle tail optimization of the crashworthiness design.