In modern electrified railway industries, the transmission quality of the electric power from the power supply to the locomotive is determined by the dynamic performance of the catenary-pantograph interaction. The mathematical modelling is a high-performance tool to study the dynamic behaviour of the catenary-pantograph system. In order to improve the calculation efficiency, a moving mesh method is implemented with a nonlinear finite element model of catenary. The contact wire is re-meshed according to the contact point between the pantograph and the catenary in each simulation time step. Addressing the unbalanced forces caused by re-meshing the contact wire, an iterative procedure is proposed based on the equilibrium equations of the flexible cable element. Through the analysis of simulation results, the proposed method shows good performance in improving the simulation efficiency and eliminating unbalanced forces. The comparison with the measurement data demonstrates the preliminary validation of the proposed method.