Real-time and accurate operation data are the basis of online operation analysis and intelligent control management of active distribution network. In order to solve the problem that the estimation result of the distribution network is not ideal by the insufficient of real-time measurement

a state estimation method of active distribution network based on Forney-type factor graph is proposed according to the belief propagation(BP)algorithm in the communication field. Considering the measurement scarcity of specific users and the randomness of distributed generator under the influence of climate

a priori distribution is firstly obtained through the historical load curve to establish a statistical Forney-type factor graph model

in which the irradiance and wind speed for the distribution network are taken into account. Then

the BP algorithm is used to globally reason the bidirectional local confidence and state information of variable nodes and factor nodes to obtain the edge distribution of each state variable. Through the simulation of the 11-node distribution network system in a certain area and IEEE 33-node distribution network system

the results show that the proposed method has good real-time performance and better estimation results under the condition of insufficient real-time measurement.