For the single-phase earth fault in the distribution network, this paper proposes two kinds of effective fault location methods. In the offline state, firstly the same high voltage pulse is injected to three-phase and the line-mode voltage signal is gathered at the head of the line; then, the same high voltage pulse is injected to three-phase and the line-mode voltage signal is adopted at the end of the line, which is called doubled-side injection method. And the same high voltage pulse is injected to three-phase and the line-mode voltage signal is gathered at the head, end and some necessary secondary branch ends of the line under the outline state, which is called the way of single-ended injection, multiterminal detection. Both methods use the relationship between the first nonzero mutation point moment of the line-mode voltage with fault distance. Through theoretical derivation, PSCAD simulation and Matlab analyzing, it proved that the single-ended injection method is more efficient than the double-side injection method, and the single-side injection can locate fault accurately.