Abstract: In allusion to the fact that there are few incremental updates and layouts for the stock single-line diagram in the distribution network, for this reason, a method to automatically generate a distribution network single line diagram, which supported the incremental updates, was proposed. Firstly, based on connected relation of device topology a connection relation mapping tree, in which the root was the power supply, was constructed. Secondly, according to the coordinates of the stock single-line diagram the assignment of layout direction was conducted for each device to obtain the device connected relation mapping tree with layout direction. Finally, according to the reverse stitching of the device layout direction the initial layout and partial contraction of the device was completed. Based on the connection relation among devices the wiring was completed, thus a distribution network single-line diagram, which inherited the original layout, could be obtained. The proposed method to automatically generate distribution network single-line diagram supporting incremental updating was applied to the development of automatic generation system for distribution network thematic map, and its effectiveness was verified by engineering projects.