Interference　fit　is　widely　uesd　in　the　high-speed　coupling　of　micro　gas　turbine　since　it　can　transfer　large　torque,　are　easy　to　produce　and　offer　significant　cost　advantages.　In　this　paper,　a　interference　fit　model　was　developed　to　analyse　the　contection　strength　of　coupling　and　shaft　for　micro　gas　turbine.　Then　using　elastic　theory,　the　radial　stress,　tangential　stress　and　radial　displacement　of　high-speed　coupling　are　derived　with　taking　account　of　contact　pressure,　angular　velocity　and　the　thickness　of　coupling.　Finally　taking　a　100kW　micro　gas　turbine　as　an　example,　the　above　solutions　were　calculated　by　using　the　numerical　method　and　results　show　that　the　contact　pressure,　angular　velocity　and　thickness　of　the　coupling,　should　be　considered　for　the　design　of　the　interference　fit　between　the　coupling　and　shaft　in　micro　gas　turbine.　The　direction　of　the　radial　stress　of　the　coupling　is　determined　by　the　value　of　the　contact　pressure.　The　tangential　stresses　of　the　coupling　are　identically　greater　than　zero.　The　radial　displacement　of　the　coupling　is　a　monotony　decrease　function　of　the　radius　and　positively　correlated　with　the　contact　pressure,　angular　velocity　and　thickness　of　the　coupling.　©　Published　under　licence　by　IOP　Publishing　Ltd.