The　stiffness　of　oily　interfaces　can　be　divided　into　two　parts,　solid　contact　stiffness　and　liquid　oil　film　dynamic　stiffness;　meanwhile　the　two　parts　are　shunt　connection.　Using　fractal　theory　of　contact,　the　model　for　normal　solid　contact　stiffness　of　the　oily　interface　was　established,　which　is　related　to　the　area　of　actual　solid　contact　surface;　on　this　basis,　the　area　of　the　oil-filled　contact　is　the　difference　between　nominal　contact　area　and　actual　solid　contact　area,　and　the　model　for　oil　film　normal　dynamic　stiffness　of　porous　oily　material　fixed　joint　interface　was　set　up　based　on　the　average　flow　of　generalized　Reynolds　equation.　The　model　for　normal　comprehensive　dynamic　stiffness　both　can　be　easily　obtained　considering　the　shunt　relationship.　Through　simulation　and　comparing　to　previous　experimental　results,　the　correctness　of　the　modeling　method　was　verified.　Results　show　that　the　stiffness　of　joint　interfaces　can　be　effectively　improved　with　oil　media　filled　into　the　interface.　In　addition,　using　of　oily　porous　material,　that　is,　self-lubricating　material　is　proved　to　be　an　effective　proposal　for　oil-filling　between　the　joint　interfaces.