The invention relates to an automatic reclosing method for multiphase faults of an extra-high-voltage common-tower double-circuit transmission line, which comprises the following steps that: 1) faults of double circuits of a system are detected; 2) according to detecting results obtained in the step 1), when a situation that the double circuits of the system simultaneously respectively have a one-phase fault is detected, a protection action is performed, so that a circuit is subjected to three-phase tripping, the other circuit is subjected to fault-phase tripping, and a time T1 later, a single-phase tripping circuit is subjected to single phase reclosing; and 3) a time T2 later, a three-phase tripping circuit is subjected to three-phase closing, so that the line is put into operation again. By using the method disclosed by the invention, a situation that double circuits trip off in case the reclosing of the double circuits is not successful can be effectively avoided, thereby improving the safety and reliability of the system.