In the process of reversing the load of the distribution network, the loop current formed during the loop operation is large, resulting in the failure of the load transfer, and with the access of new energy, the load transfer is more and more complex. In order to quickly and efficiently conduct the load transfer of distribution network, a load transfer optimization model of source and load uncertainty is proposed. Firstly, the calculation method of measuring the coupling characteristics of the transmission element namely the transmission impedance electrical distance method is proposed. By describing the coupling degree between elements, the goal of reducing the loop current is achieved, forming an electrical distance constraint condition. Then, by integrating the safety constraints of load transfer and the objective function of minimizing the total number of switch operations, the uncertainties of distributed generation (DG) and load are analyzed to obtain the chance constraints of loop closing current, establishing an optimal load transfer model that accounts for the uncertainties of sources and loads. Finally,the wiring configuration of a regional distribution network is analyzed to verify the feasibility and effectiveness of the proposed model.