On the basis of orthogonal test,mechanical properties of plastic-steel fiber concrete were studied.Three factors were selected for this test,namely the amount of mixing rubber,rubber modification method and the content of steel fiber.The results indicate that adding steel plastic fiber can partly compensate for the adverse effects of rubber on concrete strength.With the increase of the content of steel fiber,the strength of rubber concrete increases.The modification treatment of rubber is beneficial to the binding between rubber and cement matrix,and optimizes the mechanical properties of rubber concrete.The method of Al_2(SO_4)_3 solution immersion is the best for mechanical properties of rubber concrete.Based on the optimization results,the stress-strain constitutive equation was given for different dosage of steel fiber reinforced concrete.