To improve the locating efficiency and accuracy of the fault location matching the rigorous positive sequence auxiliary increasing coefficient (PSAIC), a fast fault location method is proposed for the rigorous PSAIC calculation for phase distance protection. First, based on the bus impedance matrix and the modified formula of matrix elements, the expression of PSAIC is derived, and the 13 possible PSAIC variation trends with fault location movement are obtained. Then, by analyzing the PSAIC variation pattern with fault location movement, five selection criteria for fault location matching the rigorous PSAIC are established, and a fast fault location method is proposed suitable for various network structures. Finally, the method’s efficiency are verified by the IEEE multi-bus benchmark test system. The locating accuracy is more elevated than the procedure locating method, and the efficiency is higher than the multi-location method.