To solve the problem that high impedance grounding fault of distribution network is easy to be confused with capacitor switching and load switching due to weak characteristics, an identification method based on improved variational mode decomposition and characteristic distribution coefficient is proposed in this paper. Firstly, the variational mode decomposition algorithm is used to deal with the transient zero-sequence current of the line, and several mode components are obtained. Among them, sparrow search algorithm is used to optimize and determine the parameters of variational mode decomposition. Then, the mode with the largest kurtosis is selected as the characteristic mode, the envelope distribution histogram is drawn, and the kurtosis, standard deviation and axial section sampling discriminant coefficient are calculated. Finally, according to whether the comprehensive characteristic distribution coefficient exceeds the threshold value, the high impedance grounding fault and disturbance events can be distinguished under different conditions. The reliability of the algorithm is verified by a lot of simulations on PSCAD/EMTDC software.