Abstract:Preceeding from the current situation of low voltage problem in low density load area in Sichuan province,and based on the relevant specifications of 10 kV medium - voltage line in " The Guide of Planning and Design of Distribution Network", the modeling and simulation of terminal voltage with different wire diameter and different load capacity of 10 kV overhead lines are carried out with DIGSILENT software,and thus the reasonable power supply radius when hanging different loads is derived. The related research results can be used as a detailed supplement to the existing standards for power supply radius of 10 kV overhead line of State Grid Corporation of China.