We apply the linear active disturbance rejection control (LADRC) to the speed sensorless control of the flux-switching permanent magnet motor (FSPMM), and construct a speed observer of the FSPMM by using a linear extended state observer (LESO) to achieve accurate and fast real-time estimation of the speed. We use the LADRC as a regulator of the speed loop, and this improves the robustness of the system. Simulation results show that the designed sensorless LADRC strategy based on LESO can make FSPMM run stably and reliably. The LESO improves the observation accuracy, response speed and overcomes the high-frequency chattering caused by the sliding mode observer (SMO). Compared with sensorless PI control strategy based on SMO, the proposed control strategy is more robust to load disturbance and parameter perturbation.