In order to solve the nonlinear control problem such as clearance and friction existing in the electric servo loading test bench,the sliding mode variable structure control (SMC) was used as the main body to design the loading controller.The whole structure of the servo loading test bench was studied,and a fuzzy sliding mode control (FSMC) strategy based on extended state disturbance observer (ESO) was proposed.On the basis of using ESO to observe the external interference of system,the fuzzy control was designed to adjust the sliding mode surface and sliding mode approach law adaptively,which improved the dynamic real-time following ability and interference compensation ability of the system,and reduced the chattering of the SMC.The simulation results show that the designed fuzzy sliding mode controller based on extended state observer has faster response and robustness than SMC and PID controller.