High　speed　permanent　magnet　synchronous　motor　with　high　power　density,　compact　structure,　and　the　advantages　of　small　volume,　in　many　cases　has　incomparable　advantages　with　other　motor,　the　emerging　of　new　energy　vehicles　industry,　in　particular,　powered　by　hydrogen　fuel　cells　as　a　hydrogen　fuel　cell　car　in　the　application　of　air　compressor　has　very　broad　application　prospects.　In　this　paper,　a　20KW,　5000r/min　high-speed　permanent　magnet　motor　used　to　provide　power　for　a　high-speed　bearing　test　bed　is　taken　as　the　experimental　object.　The　main　contents　include:　First　of　all,　this　paper　summarizes　the　existing　experience　and　proposes　the　design　process　of　high-speed　permanent　magnet　motor,　aiming　at　reducing　high　harmonics　and　simplifying　the　structure　to　complete　the　design　of　stator　and　rotor.　Then,　based　on　time-step　finite　element　method,　Ansoft　Maxwell　software　was　used　for　simulation　analysis　to　verify　the　rationality　of　electromagnetic　design　of　the　motor.　©　2020　IEEE.