The invention relates to a loop-closing current online calculation method of a power distribution network. The method is technologically characterized by comprising the following steps that 1, regional scheduling data is transmitted for provincial scheduling; 2, integral state evaluation is conducted on provincial scheduling and regional scheduling; 3, data is integrated; 4, the consistency of online parameters and off-line parameters is checked; 5, topology island analysis is conducted; 6, load flow calculation and data issuing are conducted; 7, loop-closing current calculation is carried out. By means of the method, the convergence of loop-closing current calculation of load flow data is greatly improved, the quality and efficiency of loop-closing current calculation are thus substantially improved, and the efficiency of scheduling loop-closing operation is improved.