In a Permanent Magnet Linear Synchronous Motor (PMLSM) with segmented stators, when the mover enters and exits the stator, the control performance was degraded due to the detent force, load disturbance, frictional force, parameter perturbations, and coupling area variations. To address this drawback, a switching control method was proposed. First, an improved Sliding Mode Control (SMC) was used to reduce the speed ripple during the complete coupling stage of the mover and the stator.Then, the chattering caused by the SMC was reduced by the Disturbance Observer (DOB). When the mover exits the stator, thefunction relationships between the electromagnetic parameters and the position of the mover were established to compensate for the speed loss caused by the variation of the coupling area in real time. The results from thesimulation and experiments indicate that the speed ripple is decreased to 0.005 m/s and the setting time is less than 0.3 s in the complete coupling stage.The speed loss is reduced to 0.04 m/s when the mover exits the stator, thereby satisfying the requirements for stability and rapidity of the system.