Disclosed are a speed-increasing gear lubrication device and lubrication method that are able to prevent air from mixing with the lubricating oil due to lubricating oil splashing at startup, without requiring a long time to heat the lubricating oil. The speed-increasing gear lubrication device has a speed-increasing gear that has an input shaft, a gear group that is turned by the rotation of said input shaft, and an output shaft that is turned by the rotation of said gear group and that increases the speed of rotation from the aforementioned input shaft through the aforementioned gear group and transmits same to the aforementioned output shaft, an oil storage chamber in which lubricating oil for lubricating the aforementioned speed-increasing gear is stored, and a lubricating oil circulation line that supplies the lubricating oil stored in the aforementioned oil storage chamber to the aforementioned speed-increasing gear by means of a pump and returns lubricating oil that has lubricated the speed-increasing gear to the aforementioned oil storage chamber. Provided in the aforementioned lubricating oil circulation line are a bypass line that bypasses the aforementioned speed-increasing gear, and a switching valve that switches either to supply the aforementioned lubricating oil to the aforementioned speed-increasing gear or to send the oil through the aforementioned bypass line.