The invention discloses a multiline concurrent loop closing method, which comprises the steps as follows: a main distribution network model is obtained and spliced; the spliced main distribution network model is subjected to network topology analysis; a node-branch power network model is built by determining buses as nodes and connecting equipment between the buses as branches; node voltages of the nodes are obtained; the node voltages of the nodes include node voltage phases and node voltage amplitudes of the nodes; a concurrent loop closing admittance matrix is obtained; the concurrent loop closing admittance matrix comprises a conventional node admittance matrix and a concurrent loop closing increment matrix; loop closing currents of various loop closing switches are calculated on the basis of the concurrent loop closing admittance matrix and the node voltages of the nodes; whether the loop closing currents exceed a protective limit or not is judged; and if not, the loop closing switches in the main distribution network model are simultaneously turned off. Therefore, the load transfer efficiency is greatly improved; the load transfer time is shortened; and furthermore, induction of large-area blackout is further avoided.