The　working　speed　of　the　high-speed　magnetic　suspension　rotor　system　should　avoid　its　critical　speed　distribution　range　to　obtain　a　better　operational　effect.　In　this　paper,　the　dual-stator　bearingless-flux　switching　permanent　magnet　motor　with　rotor　five-degree-of-freedom　suspension　is　regarded　as　the　object.　Firstly,　the　system　structure　and　operation　principle　are　introduced.　Then,　the　relationship　between　the　axial　and　radial　support　stiffness　and　the　structural　parameters　of　the　motor　system　was　explored　respectively,　and　the　linear　support　stiffness　was　calculated.　Finally,　the　finite　element　model　of　the　rotor　is　established,　and　the　critical　speed　of　the　suspended　rotor　under　different　radial　and　axial　support　stiffnesses　were　calculated　respectively,　which　provides　a　theoretical　basis　for　the　deviation　of　critical　and　working　speed　of　the　system.　©　2023　IEEE.