A fault location algorithm for extra-high voltage（EHV）mixed lines based on fault zone identification is proposed. Fault zone identification method is developed using the uniform transmission line equations，with overhead-cable line connection point as references.Fault point positioning functions in different sections are derived and the accurate position of the fault point can then be obtained by searching algorithms.A method to identify and revise the asynchronous angle is proposed to handle the problem of asynchrony between data from two different terminals.Finally，the influence factors of the algorithm accuracy are analyzed.The proposed algorithm is not affected by transition resistance.It is computationally efficient with high precision.