A distribution network management system includes a power generation device including a renewable energy power generation source, and is connected to a distribution network through a first node; a first distributed device including a first distributed resource, connected to the distribution network through a second node, and configured to receive first node information and power generation information from the power generation device and attempt to control the first distributed resource so that an overvoltage for the first node is resolved; and a second distributed device including a second distributed resource, connected to the distribution network through a third node which is located farther away from the first node than the second node, and configured to, when the first node information and the power generation information are received from the first distributed device, attempt to control the second distributed resource so that the overvoltage for the first node is resolved.