A numerical model for piston dynamics and lubrication analysis is proposed by coupling the lubrication model of piston skirt-liner system and the dynamics model of multibody system consisting of crank, connecting rod and piston. The lubrication model is solved by the Finite Element Method, while the multibody dynamics equations are established with Lagrange multipliers and constraint Jacobian matrix. The validation of the method is verified through comparing with a well-known existing work. Apart from this, some design parameters of piston skirt were investigated so as to reveal their influence on the slap noise and lubrication performances of the piston. (C) 2015 Elsevier Ltd. All rights reserved.