A　three-dimensional　W-M　fractal　sliding　model　of　double　rough　surfaces　was　established,　and　considering　the　factors　which　contained　interface　shear　strength,　sliding　speed　and　normal　load　influenced　the　whole　sliding　process.　The　friction　coefficient　of　sliding　processes　was　analysed　using　the　finite　element　analysis　taking　into　account　adhesion　factors　in　the　process　of　contact.　The　numerical　results　show　that　the　average　coefficient　of　friction　is　as　0.28　under　the　boundary-lubricated,　the　average　coefficient　of　friction　is　as　0.713　under　the　unlubricated　interfaces,　the　average　coefficient　of　friction　is　as　0.73　under　the　max　interfacial　shear　strength.　With　the　decrease　of　the　interface　shear　strength,　the　increase　of　normal　load　and　the　increase　of　sliding　velocity,　the　average　coefficient　of　friction　is　decreased.　Compared　with　experimental　results　or　related　documents,　it　is　concluded　that　the　results　are　of　rationality,　these　results　also　provide　theoretical　reference　for　the　tribological　design　and　preparation　of　friction　materials.