Method for preventing distance protection maloperation of superior line caused by sympathetic inrush current

The invention relates to a method for preventing distance protection maloperation of a superior line caused by sympathetic inrush current. Comprising the steps that a protection device is started, when a distance III section impedance element acts, phase current direct current, secondary harmonic components and third harmonic components are extracted, and when it is judged that a certain phase or multiple phases of direct current components suddenly change and are in an attenuation trend, judgment is carried out in sequence, the second harmonic content of a certain phase or multiple phases is larger than 15% and the third harmonic content is smaller than the second harmonic content within 0-40 ms; (2) within an interval of 40-90ms, the second harmonic content is reduced, the third harmonic content is increased, and the third harmonic content is always greater than the second harmonic content after a certain moment; (3) after 90 ms, the second harmonic is further reduced, the harmonic content is mainly third h