The utility model relates to a shaft sleeve of a transmission shaft of an isolating switch, which can continuously contain oil, and further ensures that the transmission shaft can sensitively act at any time during the long-term usage. The inner surface of a shaft sleeve body is provided with a straight oil groove from up to down, and the upper part of the body is provided with an oil filling hole communicated with the outer part and the straight oil groove. In the utility model, the original shaft sleeve inner wall is modified into a shaft sleeve inner wall with a straight groove (the straight oil groove) and a spiral groove (oil groove), so that the penetration effect of lubricating oil to the lower part of the shaft sleeve and other parts can be strengthened, and the penetration rate can be quickened. In addition, in order to further improve the sealing effect of the shaft, the upper part of the shaft sleeve is provided with a cycle of upper oil groove which can seal the upper part of the shaft and can prevent water from entering, the lower part of the shaft sleeve is provided with a cycle of lower oil groove, which can seal the lower part of the shaft, and the lubricating oil can be prevented from flowing out by utilizing the stickness of the lubricating oil after the lubricating oil is accumulated.