From the design point of view, the audible noise(AN) on rainy days is the most concerned parameter. For 1000kV UHV AC lines, many prediction methods for rainy days are mainly based on the statistical data of the test lines, and do not take into account the variation of rainfall deeply. In this paper, the first long-term observation station has been established under the Huainan-Shanghai 1000kV UHV AC double-circuit transmission line which has been in operation for 2 years, and the AN test has been carried out for one year. The statistical results during rain in different seasons and the influence of rain rate are analyzed, and compared with the longterm test statistical results of 1000kV UHV AC single circuit line. The statistical prediction method for AN of 1000kV UHV AC transmission lines during rainy days is proposed.