Background　and　Objectives:　The　existing　medical　clinical　treatment　institutions　mostly　use　rigid　structures　to　come　into　contact　with　flexible　skin.　The　rigid　flexible　coupled　contact　biomechanical　model　for　the　skin　is　the　first　step　that　urgently　needs　to　be　considered　in　the　process　of　medical　clinical　operations.　However,　there　has　been　currently　no　effective　biomechanical　contact　model　available.　Methods:　Based　on　the　principle　of　elastic　interface　deformation,　the　basic　biomechanical　characteristics　of　oral　and　maxillofacial　skin　and　soft　tissues　were　analyzed　to　address　the　unknown　mechanism　of　rigid　body　and　maxillofacial　contact　in　oral　imaging　operations.　A　nonlinear　characterization　method　for　the　mechanical　properties　of　oral　and　maxillofacial　skin　soft　tissues　was　proposed　by　deriving　a　general　contact　force　model　that　takes　into　account　energy　dissipation.　However,　the　problem　of　the　inability　to　obtain　analytical　solutions　for　the　parameters　of　the　dynamic　model　exists.　It　is　necessary　to　perform　particle　swarm　parameter　identification　on　different　nonlinear　contact　models　and　verify　the　accuracy　of　the　algorithm　through　numerical　simulation.　A　maxillofacial　contact　experiment　was　conducted　to　verify　the　operation　process　of　an　oral　imaging　robot.　Results:　After　experimental　analysis,　it　was　found　that　the　comprehensive　average　error　between　the　model　and　the　actual　contact　force　was　0.13325　N.　The　absolute　error　of　the　maximum　deformation　displacement　was　below　0.18　N,　which　verified　the　effectiveness　and　safety　of　the　contact　model　in　the　contact　process　of　the　oral　imaging　robot　system.　Conclusions:　The　results　indicate　that　the　output　force　of　the　model　has　been　in　good　agreement　with　the　actual　contact　force.