Abstract: This paper mainly elaborated some new problems on the fault location for half-wavelength transmission lines, and studied its fault location method. The results of the research show that the traditional double -terminal fault location method has poor accuracy in half-wavelength transmission lines. While adding the traveling wave detection units along the line and using the three-point method can effectively improve its fault location accuracy. In addition, simulation results indicate that with the increase of the number of detection points, the accuracy of fault location is gradually improved. But when the distance between two adjacent detection points is reduced to a certain extent, the location accuracy is no longer improved. It is reasonable to take 200-300km between adjacent detection points. For the capacitance tuning network, the arrangement of the measuring points also should ensures that the number of capacitors between the fault point and the three nearby measuring points is sufficiently small.