Kinetics of the hydrogels responsive to electric stimulus due to an externally applied electric field is modeled for the first time through transient simulation. The mathematical model employed is called the multi-effect-coupling electric-stimulus (MECe) model, which is developed with consideration of multi-phases and multi-physics. Transient simulation by the MECe model is examined with available experimental data and good agreement is achieved. The kinetics of ionic concentration of diffusive species is simulated. The simulation also predicts the influences of several important parameters on the hydrogel deformation, including the externally applied electric voltage, initially fixed charge density and surrounding bath solution concentration.