For distributed drive electric vehicles，less attention is paid to the inhibition of lateral torque distribution on wheel slip ratio and its improvement on cornering performance. To solve this problem，taking the advantage of the independently controllable torque，a torque vectoring control method based on tire longitudinal stiffness estimation and optimal slip ratio identification was proposed to reduce the average slip ratio of the driving-axle. According to the simplified adhesion characteristics of the tire and the road，the impact of torque vectoring on the average slip ratio of the driving-axle was theoretically analyzed. An estimator based on Recursive Least Square method（RLS） was designed to estimate the tire longitudinal stiffness in real time. On the basis of the estimated tire longitudinal stiffness and identified optimal slip ratio，an torque vectoring control method was developed. The simulation results show that，the proposed torque vectoring control method not only can obviously decrease the average slip ratio of the driving-axle by more than 10%，but also can reduce the steering wheel angle input by about 14%，which achieves the dual purpose including the improvement of cornering efficiency and the enhancement of steering maneuverability.