In order to solve the difficulty when identifying the high-resistance ground faults in resonant grounded distribution networks, this paper proposes an identification method for based on multi-frequency admittance measurements. An equivalent circuit for injecting characteristic signals is established. By injecting multi-frequency current signals into the distribution network, and measuring the return voltage signal, the parameters of multi-frequency admittance and damping rate in the distribution networks can be obtained. The incremental damping rate generated by the fault transition resistance is superimposed to effectively amplify the fault characteristic signals, and thus the influence of interference can be reduced so as to effectively identify the high-resistance ground faults. A typical 10kV distribution network is established via the PSCAD / EMTDC to simulate the ground faults under different operating conditions. Simulation results show that the method can explore ground fault characteristics by superimposing the system's incremental damping rate under multi-band characteristic signals. This validates the high anti-noise ability of this method when identifying high resistance ground faults.