A new fault location algorithm based on the distributed parameter transmission line model is proposed. The method is not affected by the saturation of current transformers or failures/deformation of current signal at one terminal. The voltage and current profiles along a transmission line are calculated by using sequential network models， the two terminal voltages and the currents from the unsaturated end. Since fault impedance is of pure resistance， the fault can be accurately located at where the phase angle between the voltage and current is zero. Results of ATP-EMTP based simulation prove that the method is correct and efficient.