To consider the impact of distributed power source integration and source?load uncertainty on the division of supply units in the distribution network, a method that takes into account fuzzy chance constraints is proposed for supply unit division in an active distribution network. Firstly, a supply unit division framework that takes into account the impact of distributed power source integration and its uncertainty is established. Secondly, with the goals of minimizing the number of supply units and optimizing load balance, a supply unit division model that considers fuzzy chance constraints is built. Thirdly, based on the clear equivalence treatment of fuzzy variables, an iterative solution method is proposed for supply unit division between and within stations. Finally, the proposed model and method are explained by calculation example simulation. And their effectiveness and practicality are verified.