An adaptive forecasting method of branch power of the urban power grid is presented. The implementation is accomplished by utilizing three basic load forecasting methods using Multi-model technology. After forecasting the load of one bus, two methods are used to get the branch power including distributing bus load and forecasting it directly with history data. The proposed branch power forecasting method is tested on one urban power grid. The simulations imply that the adaptive method is more efficient than that using single model.