Aiming at the common current loop， speed loop and position loop control structure of dual-motor synchronous anti-backlash servo system， a simplified control strategy with stronger robustness and faster response speed is proposed. The positon controller of the servo system is designed based on the backstepping theory and the torque reference command is directly calculated and transmitted to the current loop from the reference position command after command-filter processing, which simplifies the control structure. The integral nonsingular terminal sliding surface is introduced in the backstepping controller design process which overcomes the chattering problem of the linear sliding mode control and makes the system reach the equilibrium state in finite time. The extended state observer （ESO） is adopted to compensate the external disturbance which makes the servo system more robust to the changes of the internal structure parameters and external disturbance torque. The co-simulation experiment is carried out in Matlab/Simulink and Adams and the results show that the proposed new dual-motor synchronous anti-backlash method has better tracking performance than tradition scheme and better anti-disturbance ability than the ordinary disturbance compensation method.