Aiming at the system identification method of a single degree of freedom electromagnetic vibration energy collecting device with complex nonlinear restoring force, a harvestervoltage mapping identification method was proposed.With this method,the electromagnetic electromechanical coupling function,the equivalent inductance function,the damping restoring force function and the elastic restoring force function of the acquisition system could be identified without knowing the specific forms of the mechanical function and electrical function.The model example containing quintic polynomial nonlinear restoring force was used for simulation verification,and the time history response of the example under simple harmonic excitation was calculated by using the RungeKutta method; by using the voltage mapping method,the electromagnetic coupling function,equivalent inductance function,stiffness function and damping function of the system were successfully identified.Compared with the accurate results,the identification results have good consistency.