Based on the observed bird behavior in Hunan and the fault characteristics of bird-related outage in Hunan Power Grid from 2006 to 2016, the bird-related outage risk for overhead transmission lines in Hunan Power Grid is analyzed. The results showed that the high level of risk regain for guano-caused damage is mainly concentrated in northern Hunan, east central Hunan and west Hunan. The area of III level of guano-caused risk regain accounts for about 5.03% of the total area of Hunan power grid, while the II level risk area of 15.24%, and the I level risk area of 79.73%. The high level of risk regain for bird nest-caused damage is mainly concentrated in northern Hunan and eastern Hunan. The area of III level of bird nest-caused risk regain accounts for about 5.23% of the total area of Hunan power grid, while the II level risk area of 16.12%, and the I level risk area of 78.65%.The bird-related outage risk distribution map of overhead transmission lines in Hunan Power Grid is drawn, and the application suggestions of the risk distribution map are also proposed in the paper.