The invention discloses a distribution line single-phase grounding line selection method based on direction traveling waves, and the method comprises the steps: collecting the polarities of zero-modecurrent traveling waves and zero-mode voltage traveling waves at the head ends of all main lines and branch lines when traveling wave disturbance happens to a line, and judging the directions of initial traveling waves of all main lines; when the initial traveling wave of a certain main line is a reverse traveling wave, judging that the line is a fault line and the other lines are normal lines; after determining the fault main line, continuing to judge the initial traveling wave directions of all branch lines connected with the main line; when the initial traveling waves of all the branch lines are forward traveling waves, judging that a fault occurs in the main line; and when the initial traveling wave of one branch line is a reverse traveling wave, judging that the branch line is a faultline. According to the invention, accurate line selection of the single-phase grounding fault of the distribution line is realized and a branch line is accurately selected, so that a foundation is laid for rapidly and selectively removing the single-phase grounding fault from two ends of the line.