Topology automatic identification of power distribution network is the foundation of power flow calculation, state analysis and other advanced applications. Its identification speed and accuracy will indirectly affect the power supply reliability of power distribution network. In this paper, an automatic identification strategy of distribution network is proposed. Firstly, the large distribution network is decomposed into the combination of basic topological units, so as to obtain the static topological structure of distribution network. Then combining with the neural network algorithm, the paper realizes the identification of the branch state change of the distribution network, and achieves the purpose of dynamically updating the real-time change of the distribution network topology. Finally, the effectiveness of the strategy is verified by MATLAB simulation analysis.