To make up disadvantage of error convergence speed and smoothness on the noncomplete constraint trajectory tracking of mobile robot control. A improved nonlinear backstepping tracking control method was designed. On the basis of the kinematic model, a simple dummy variables was constructed and then backstepping control law was deduced, and the stability of the control law was proved by Lyapunov function, also a feedback control was inserted, and then a new trajectory tracking controller was got. MATLAB simulation results show that the improved nonlinear backstepping control law well have been improved, the tracking error can converge in a short period of time, has a good antijamming capability. 