Abstract: Aiming at the fault location of hybrid lines in transmission lines, the characteristics of traveling wave propagation in hybrid lines are analyzed, and a double-terminal location method based on time discrimination method is proposed. Firstly, the fault region is determined by using the travelling wave polarity, and the arrival time of the fault transient travelling wave is recorded in the measuring sections at both ends of the line. Then, the time difference of arrival of travelling waves at both ends is compared to obtain the fault location result based on the principle of two-terminal location. The results show that the method is accurate and reliable in fault location of mixed lines.