The invention relates to a fault positioning device and a positioning method based on distribution network line state monitoring, fault early warning and positioning technology using distributed-type phasor measurement, comprising a current monitoring unit, a voltage monitoring unit, a gathering unit and a main station. In normal operations, the voltage monitoring unit and the current monitoring unit transmits the obtained load voltage and the current data at specific points of the lines to the gathering unit every fifteen minutes. The gathering unit analyzes and processes the data and then uploads the data to the main station, and the main station directly presents the states of the distribution network lines in the form graphs, curves, tables and other interface display ways. The device and the method of the invention are low in cost and of a high performance-to-cost ratio. The device can be installed with power on, and is free of maintenance. The device and the method are able to obtain and record the current and voltage waveforms at various monitoring points, and are able to accurately position the sections with single-phase grounding fault and short-circuit fault.