The invention provides a wind power gear box. The wind power gear box comprises a front tank, a rear tank, a planet gear transmission mechanism and a parallel shaft transmission mechanism. The planetgear transmission mechanism comprises a first-stage planet gear train and a second-stage planet gear train. The first-stage planet gear train comprises an input shaft, a compound planet carrier, a compound double planet gear, a long planet gear shaft, a compound planet gear, a short planet gear shaft, an inert sun gear, a first-stage sun gear and a first-stage inner gear ring. The compound doubleplanet gear comprises a small planet gear body and a large planet gear body. The small planet gear body and the compound planet gear are in engaged transmission with the inert sun gear and the first-stage inner gear ring, and one way uniform loading is achieved; and the large planet gear body and the first-stage sun gear are in engaged transmission, and another way uniform loading is achieved. Thesecond-stage planet gear train comprises a second-stage sun gear, a second-stage inner gear ring, a flange, a second-stage planet gear and a planet gear shaft. According to the wind power gear box, multi-stage planet row unbalance loading can be suppressed, and system transmission is steadier.