The characteristics of residential load and its development trend forecast will help to scientifically build electric vehicle charging facilities, and ensure the safe and reliable operation of residential power supply facilities. Based on the research on the charging characteristics of electric vehicles, this paper establishes the mathematical model of charging load demand of electric vehicles connected to power grid, and analyzes the influence of charging facilities on the load characteristics of residential areas, and then proposes a charge forecasting and capacity allocation method. Finally, two typical stations are selected to simulate the load of the zone before and after the electric vehicle access, and the effectiveness of the proposed method is validated.