Abstract: The structure and characteristics of the overhead line-to-cable hybrid transmission lines are quite different, resulting in different wave speeds and wave impedances. When the fault traveling wave propagates to the connection point between the overhead line and cable, a strong wave reflex phenomenon will occur, resulting in an increase in the traditional traveling wave ranging error, leading to traditional single-ended traveling wave fault location algorithm cannot be directly applied to the overhead line-Cable hybrid transmission line. This paper proposes a new fault location method based on K-means algorithm in the above situation. First this method decomposes the fault current component by db4 wavelet decomposition and extracts the wavelet coefficients at the sixth scale, and correlates it with historical fault data. Secondly the related data is filtered and classified by the K-means algorithm to extract the most relevant five groups data. finally we calculate the fault distance by regression equation. This method does not need to obtain the wave speed and the length of the line. To a certain extent, the measurement error that these factors may cause is avoided. It can provide reference for fault location of transmission lines.