An electromechanical model is presented to predict the nonlinear large deflection behavior of ionic polymer-metal composite (IPMC) cantilever actuators under different DC voltages applied. In the paper, authors combine the relationships between IPMC strain gradient and excitation voltages obtained by digital image correlation (DIC) with the modified model of IPMC electrode distributed resistor-capacitor (RC) circuit, propose the analytic solution for the electromechanical behavior of IPMC actuators, and verify experimentally the model using Pt-IPMC and Ag-IPMC samples. The results demonstrate that the electromechanical model can accurately describe the bending deformation of IPMC cantilever actuators under DC voltages applied, and is suitable for the IPMC actuators with electrodes prepared by the deposition method.