The definition of the distribution communications network is presented along with the distribution communication network physical composition and its importance in power system communication.By analyzing the distribution communication network undertaking the principal transactions and their characteristics，a model for the distribution communication business section is proposed.By analyzing the flow calculating method of different business cross-sections，the traffic bandwidth calculation basis is provided to a variety of types of sites and different distribution partitions.The A+ regional electricity distribution business flows is taken as an example to show how the business flow and its calculation is analyzed in accordance with the business section model and the business flow calculation method.Finally，the total traffic of different regions of the distribution automation business is given for reference by network communication planning and design.The sectional flow model provides intelligent electricity distribution network communication with effective means of assessing technical type options，bandwidth forecasting，planning and design，contributing to planning and construction of the power system of both prefectural and municipal backbone distribution communication networks.