A pilot protection method of T-connected transmission lines is proposed in this paper. First, the startup information of each segment in three-terminal of T-connected transmission lines can be obtained. On this basis, the pilot protection fault identification criterion can be constructed. Then, according to this criterion, the fault position can be located quickly and accurately. This method simplifies the principle of setting coordination for distance I and II segment, without the effect of non-synchronous information. Finally, the simulation result from PSCAD(Power Systems Computer Aided Design) has proved the correctness and feasibility of the proposed method.