The invention provides a voltage control method and device for a power distribution network provided with a distributed power source. The method includes the following steps that: the main nodes of each sub power distribution area in the power distribution network are obtained; the sensitivity matrix of the voltages of the main nodes and the power of the sub power distribution areas is determined;and a main node voltage allowable interval is determined, and voltage control is performed on the power distribution network provided with the distributed power source. According to the voltage control method and device of the invention, the optimized scheduling means of the distributed power source is provided; the flexible and efficient utilization of the distributed power source can be realized; a voltage quality requirement of the connection of a large-scale distributed power source into the power distribution network can be satisfied; the main nodes are adopted as the objects of voltagecontrol, so that the amount of calculation data on a global layer is decreased, and calculation efficiency can be effectively improved; and the frequent action of a control system can be avoided; andthe voltage control capability of the power distribution network with the distributed power source is improved; and the operational safety of the power distribution network with the distributed powersource is ensured.