Aiming at the problem that the transmission line with shunt reactors will automatically reclose to a permanent fault after a single-phase grounding fault and cause the secondary impact of the system, a new method is proposed to identify the nature of transient faults based on the current beat frequency characteristics of the disconnected-phase shunt reactor method. After the circuit breaker trips, the short data window of the secondary arc phase of the shunt reactor current is opened to construct a predicted waveform conforming to the sinusoidal characteristics. The sampled waveform and the predicted waveform under transient faults are quite different, and its correlation coefficient fluctuates drastically between 1 and -1, stay near 1 under permanent failure. Therefore, the cross-correlation coefficient of current waveforms can be used to reliably identify the nature of the fault. This method has low filtering requirements, simple principle and easy implementation. The PSCAD simulation results show that the fault nature identification method can accurately identify transient faults, effectively increase the success rate of reclosing, and improve the stability of system operation.