The invention discloses a distribution network regional voltage distributed coordinated control method and system. The method comprises a step of determining the installation positions of line voltageregulators in a power transmission line when there is no light, a load is maximum and a voltage loss rate is smaller than a set value, a step of dividing the power transmission line into multiple regions by using the installation positions of the line voltage regulators as boundaries, a step of establish a regional optimization model with the minimalization of the active loss of the power transmission line and the total cost of loss of photovoltaic power generation in the regions as an optimization target, a step of performing distributed coordination optimization between the regions by usingan alternating direction multiplier method and determining the optimal objective function of each regional optimization model and the boundary voltage of each region after distributed coordination optimization, and a step of determining the gear positions of the line voltage regulators by using a branch bound method, and regulating the voltage of each region of a distribution network. According to the invention, the problems of the time and space mismatch of a power supply with a high-permeability photovoltaic distribution network and the load and voltage out-of-limit can be solved.