Embodiments of the invention disclose a monitoring method and system of a low-voltage power distribution system. The monitoring method comprises the steps of responding to a user interaction operation, displaying a distributed topological graph related to the low-voltage power distribution system, and obtaining parameter information of multiple pieces of electrical equipment in the low-voltage power distribution system; and marking the parameter information of the electrical equipment on the distributed topological graph according to the positions of the electrical equipment, wherein the distributed topological graph comprises at least one of a power distribution distributed topological graph, an architectural distributed topological graph and a communication distributed topological graph.A user can determine the electrical position of certain electrical equipment in the power distribution system and the parameter information of the electrical equipment according to the power distribution distributed topological graph, can determine the position of the electrical equipment in an actual building according to the architectural distributed topological graph, and then can determine whether the equipment connected with the electrical equipment is in abnormal communication or not through the communication distributed topological graph; and through the three kinds of topological graphs, the electrical equipment in the power distribution system can be monitored effectively, and management of the power distribution system is also reinforced.