The invention discloses a flywheel energy storage device adopting a bearingless switched reluctance motor. A permanent magnetic unloading bearing, a bearingless switched reluctance motor, a flywheel rotor and a mixed magnetic bearing are sequentially sleeved between the upper end and the lower end of a flywheel rotating shaft, wherein the permanent magnetic unloading flywheel carries the axial weight of the flywheel rotating shaft; the mixed magnetic bearing on the lower end overcomes the residual weight and the dynamic load of the flywheel rotating shaft, so that the flywheel rotating shaft is guaranteed to be stably suspended in the axial direction, simultaneously two-degree-of-freedom suspension bearing in the radial direction is provided for the flywheel rotating shaft, and the other two-degree-of-freedom suspension and electric function / power generation function in the axial direction are completed by the bearingless switched reluctance motor; and by adopting the high-speed electromotion / power generation running advantage and the self-suspension function of the bearingless switched reluctance motor, the strong unloading characteristic and the controllable suspension characteristic of the permanent magnetic unloading bearing and the mixed magnetic bearing are reasonably combined, so that the five-degree-of-freedom suspension of a flywheel with low loss and high reliability is realized, the running speed of the flywheel is improved, and the system power consumption and the size are reduced.