In recent years，with the development of the economy，there are great changes in the west-east power transmission construction, the geographic conditions of the overhead line working. There are many problems in the line operation-maintenance. In this article，the author analyzed the maintenance situation of overhead line facility in his company. Combining the management requirement of the state of the electric transmission line，he classified the daily operations into 9 aspects，such as preventing the damage caused by thunder，bird strike，damage caused by wind，icing，pollution，forest fire，flood and debris flow，external damage，and the contradiction of the tree and line. And then，the author came up with some corresponding measures based on his experience and the present technology. The PDAC cycling management was carried out during the one year practice，and the manage level over the overhead transmission line has been improved obviously.