On the basis of D-type traveling wave theory, a fault location method for T-connection lines is presented which doesn’t need judge fault branch and the calculation is simple. Wave progress in T-connection lines is studied, and based on D-type traveling wave theory, two double-terminal results are calculated by using the time that the first traveling wave head generated during the fault reaches the ends of the three-terminal power lines. Various situations are simulated and analyzed by ATP simulation software and MATLAB software. The simulation results show that this method takes advantage of the initial traveling waves within a short time to achieve fault location fast and accurately.