The invention provides an electric generator arc suppression coil compensation identification method based on a transmitting voltage characteristic frequency. The method comprises the steps of after stator grounding protection maloperation and tripping, using fault recording data to measure the post-tripping characteristic frequency in the free oscillation process of transmitting voltage; comparing the characteristic frequency and the operation frequency of an electric generator, namely the working frequency 50Hz. When the working frequency is greater than the intrinsic characteristic frequency of the transmitting voltage, a circuit is capacitive; otherwise the circuit is inductive. If the circuit is capacitive, it can be determined that an electric generator arc suppression coil is in an under-compensated state; if the circuit is inductive, it can be determined that the electric generator arc suppression coil is in an over-compensated state. With the method, actual measurement and calculation for the parameters of primary systems and equipment are not needed; the method is simple and accurate and saves time.