This paper focuses on the closed-loop fixed posture positioning control of a differential wheeled robot. First, a new posture error function is proposed based on the existing kinematics model, and the state transformation is used to apply it to the existing dynamic model, and the ability of the robot to move backwards is improved by stabilizing the transformed system model. Subsequently, based on proportional-differential control, a new control law related to speed and angle is proposed to ensure that the robot first achieves the correct operating posture and maintains a relatively stable operating process when starting. Secondly, by designing the barrier Lyapunov function, the stability of the proposed control law is verified. Finally, MATLAB simulation are used to prove the effectiveness of the proposed control law.