Aiming　at　determining　the　thermal　contact　resistance　of　ball　screws,　a　new　analytical　method　combining　the　minimum　excess　principle　with　the　MB　fractal　theory　is　proposed　to　estimate　thermal　contact　resistance　of　ball　screws　considering　microscopic　fractal　characteristics　of　contact　surfaces.　The　minimum　excess　principle　is　employed　for　normal　stress　analysis.　Moreover,　the　MB　fractal　theory　is　adopted　for　thermal　contact　resistance.　The　effectiveness　of　the　proposed　method　is　validated　by　self-designed　experiment.　The　comparison　between　theoretical　and　experimental　results　demonstrates　that　thermal　contact　resistance　of　ball　screws　can　be　obtained　by　the　proposed　method.　On　this　basis,　effects　of　fractal　parameters　on　thermal　contact　resistance　of　ball　screws　are　discussed.　Moreover,　effects　of　the　axial　load　on　thermal　contact　resistance　of　ball　screws　are　also　analyzed.　The　conclusion　can　be　drawn　that　the　thermal　contact　resistance　decreases　along　with　the　fractal　dimension　D　increase　and　it　increases　along　with　the　scale　parameter　G　increase,　and　thermal　contact　resistance　of　ball　screws　is　retained　almost　constant　along　with　axial　load　increase　before　the　preload　of　the　right　nut　turns　into　zero　in　value.　The　application　of　the　proposed　method　is　also　conducted　and　validated　by　the　temperature　measurement　on　a　self-designed　test　bed.