To enhance the speed regulation performance of Permanent Magnet Synchronous Linear Motor (PMSLM) servo systems, a novel backstepping integral sliding mode control strategy based on an ESO is proposed. Initially, the mathematical model and motion equations of the PMSLM in the rotating reference frame are presented. By integrating this model with backstepping control, virtual control inputs that incorporate velocity error terms are derived. Subsequently, these virtual control inputs are integrated into an integral sliding surface and exponential reaching law, leading to the design of d- and q-axis current controllers. This approach significantly improves the system’s dynamic response speed and steady-state tracking accuracy. To further enhance the robustness of the system against external load variations, an ESO is introduced to estimate changes in external disturbances, which are then feedback into the control law in real-time. Comparative simulations with Proportional-Integral (PI) control and traditional Sliding Mode Control (SMC) demonstrate that the proposed control method exhibits superior speed regulation performance.