The　dual-drive　ball　screw　pair　serves　as　a　crucial　element　within　the　fixed　gantry　machine　tool　with　cross-rail　movement.　When　in　service,　the　dual-drive　ball　screw　pair　experiences　variations　in　axial　load,　impacting　the　contact　load　distribution　of　the　ball　screw　pair.　A　calculation　model　for　determining　the　axial　load　offset　of　the　dual-drive　ball　screw　pair　is　proposed　to　investigate　the　variation　in　axial　load.　The　impact　of　the　geometric　error　associated　with　the　guide　rail　and　the　position　of　the　slide　are　considered.　This　paper　presents　the　contact　load　distribution　model　for　the　dual-drive　ball　screw　pair.　This　study　investigates　the　contact　load　and　contact　angle　distribution　of　the　dual-drive　ball　screw　pair　during　the　machine　tool　in　service.　Additionally,　based　on　fractal　theory,　the　stiffness　models　of　individual　micro-convex　body　and　contact　surfaces　have　been　established.　This　study　provides　a　comprehensive　analysis　of　the　contact　stiffness　of　the　ball　screw　pair,　considering　the　influence　of　guide　rail　geometric　error　and　slide　position.　In　addition,　the　three-dimensional　surface　morphology　of　ball　screw　pair　is　obtained　by　experiments.　This　paper　investigates　the　contact　stiffness　distribution　of　dual-drive　ball　screw　pair　during　service.