Teed circuits with four-parallel lines on the same tower consist of four-parallel lines on the same tower and quadruple-lines on the same tower. After analyzing the fault line selection, a new method is proposed. The fault region is determined at first, and then the specific fault branch is identified. The mutual electromagnetic effect between four-parallel transmission lines is decoupled to obtain the relationship between the inverted-sequence current of two power source sides. According to that, the fault side is identified and the fault area can be determined quickly. The positive-sequence voltage difference is introduced to detect the fault branch precisely. Both a theoretical analysis and EMTP simulation results show that the method is correct and has high precision.