Abstract: The random fluctuation of the distributed generation will threaten the economy and safety of distribution network. Therefore, this paper proposes a coordinated planning method of transformer capacity expansion and distributed generation for the distribution network considering channel factor. Firstly, according to the operation characteristics of distributed generation, fuzzy variables are used to represent the output power of distributed generation, and its membership function is established to reflect the uncertainty of output power. Secondly, constraints such as distributed generation permeability and power supply radius are introduced. Based on the objective function of fuzzy expected network loss, fixed equipment investment cost and operating cost, a double-layer coordinated planning model of distributed generation with multiple control means is established. Finally, the control variables of the upper and lower levels are coded with chromosomes, and a bi-level optimization genetic algorithm is constructed. The simulation results show that the proposed method is effective in improving the economic benefits and power supply reliability of distribution network.