Abstract: Thin elastomer,as a surface functional structure,has broad application prospect in engineering. The contact behavior analysis of thin elastomer is very important for functional surface design and application. Computational generation technology of random rough surface and finite element analysis were used to develop deterministic analysis model of contact stiffness of rough thin elastomer surface. The contact characteristic of thin elastomer was analyzed,and the suitability of asperity-substrate layer series model was discussed based on semi-numerical deterministic analysis method for rough thin elastomer's contact stiffness calculation. The results show that when the thickness of a substrate layer was less than 10 times of Rq,the error of the thin elastomer's stiffness obtained by traditional asperity-substrate layer series model was more than 15%,which results from the coaction of large deformation of asperity layer and nonuniform local deformation of substrate layer.