The　main　work　of　this　paper　is　to　use　the　finite　element　method　to　establish　a　two-dimensional　finite　element　model　of　press-pack　IGBT　power　device,　and　calculate　the　temperature　change　of　each　material　layer　and　the　contact　thermal　resistance　between　each　material　layer　through　the　thermo-electric　coupling　algorithm.　Since　the　thermal　contact　resistance　between　the　Al　metallization　layer　and　the　emitter　Mo　plate　increases　more　dramatically　during　the　power　cycle　of　the　press-packed　IGBT　device,　the　two-dimensional　surface　morphology　of　the　contact　interface　between　the　Al　metallization　layer　and　the　emitter　Mo　plate　is　established　by　the　W-M　fractal　function,　and　the　influence　of　the　two-dimensional　surface　morphology　under　different　roughness　on　the　junction　temperature　of　the　press-packed　IGBT　chip　and　the　thermal　contact　resistance　between　the　Al　metallization　layer　and　the　emitter　Mo　plate　during　the　power　cycle　is　analyzed.　The　results　show　that　with　the　change　of　the　contact　interface　roughness　between　the　Al　metallization　layer　and　the　emitter　Mo　plate　in　the　press　pack　IGBT　device,　the　contact　thermal　resistance　between　the　chip　junction　temperature　and　the　material　layer　during　the　power　cycle　is　also　changing.　Therefore,　the　two-dimensional　contact　interface　equivalent　model　with　different　roughness　established　in　this　paper　can　simulate　the　surface　morphology　of　the　contact　interface　with　different　power　cycles.　©　VDE　VERLAG　GMBH.