According to the characteristics of the longitudinal impedance presented in the double-ended line, it is extended into the T-type line. On the identified fault branch, two T-line fault location algorithms are proposed. The indirect method, combined with the T-type line structure, uses the line transmission equation to transfer the electrical quantity of the non-faulty branch to the T-node and constructs the line condition using the longitudinal impedance. The accurate fault location is established with the linear relationship between the longitudinal impedance and the fault distance. The direct method, based on the original double-ended longitudinal impedance, keeps the voltage difference between the two ends constant, supplemented by the current at the other end, and forms the current of the three ends, establishing a longitudinal impedance algorithm suitable for the T-type line.In the same simulation environment, the comparative verification is carried out. The results show that both algorithms can obtain effective fault location. Under the influence of factors such as fault distance, fault type and operation mode, both algorithms are very good precision.