On October 27, at the ± 800 kV Qingyu Line No. 70 tower at an altitude of 3,600 meters in Qinghai, the operators of State Grid Qinghai Ultra High Voltage Company replaced insulators at an altitude of 70 meters from the ground, and made every effort to promote the Qinghai-Henan ± 800 kV UHVDC project. The second centralized maintenance task after the operation ensures the smooth conclusion of the annual maintenance.