Abstract: Considering that the wavelet modulus maximum method in the existing traveling wave ranging method has high requirements for the basis function and decomposition scale when applied, and modal aliasing will occur when empirical mode decomposition(EMD) is applied in the process of Hilbert-Huang transform(HHT), in order to solve the above problems and solve the problems of transmission line length is too long, the probability of fault occurrence is too large, and the ranging accuracy is relatively low Fault ranging method of UHVDC transmission line combined with Teager energy operator. When a unipolar ground fault occurs in the overhead line, the fault current traveling wave data is simulated by PSCAD, and the variational mode decomposition(VMD) decomposition of the line mode current traveling wave signal is used to obtain the optimal IMF modal component after decoupling, and the energy mutation point of the high-frequency modal component is extracted by using Teager energy operator, and the moment represented by the energy maximum value is substituted into the double-ended traveling wave ranging formula, and the precise location of the fault point can be obtained. Through the comparative analysis of PSCAD combined with Matlab simulation verification, the accuracy of the ranging method can be guaranteed in different fault locations and transition resistance.