Abstract: This paper provides a fast method based on static reduction for the solution of the displacements of the piston ring’s contact nodes.The nodal displacements and the corresponding nodal forces of the contact nodes are connected by the contact stiffness matrix which is obtained through performing static reduction on a finite element description of the two dimensional model of the piston ring in an internalcombustion engine.Given applied loads,the displacements of the contact nodes can be quickly obtained,and vice versa.The numerical result is compared with that of analytical and the error is less than 2% which indicating the accuracy of this numerical method.Using this method,free shape of the piston ring can be easily designed to ensure the requirements of the contact pressure of the piston ring,which will improve wear resistance and service life of the piston ring.