The invention relates to a power distribution network structure identification method based on a probability graph model. The method comprises steps that (1) equidistant sampling of voltage data of auser intelligent electric meter and preprocessing are performed; (2) based on the voltage data of the user intelligent electric meter, a mathematical model of a power distribution network structure isestablished by using the probability graph model, and the mathematical model represents the interrelation between intelligent electric meter nodes in the power distribution network and a power connection line; (3) the established mathematical model is simplified, an objective function is established, and unknown parameters are assumed; (4) a target function is optimized; (5) unknown parameters are solved; and (6) the relation between the nodes and the edges of the intelligent electric meter is solved according to the solved unknown parameters, and ] identification of the power distribution network structure is completed. Compared with the prior art, the method is advantaged in that the topology is identified by utilizing the intelligent electric meter data, auxiliary decision of other equipment is not needed, the method is simple, and identification accuracy is high.