The utility model discloses an oil blanket structure belongs to oily sealing technology field. Include the casing, be fixed in oil blanket on the casing is personally experienced sth. Part of the body, is worn to locate main shaft on the oil blanket body, be equipped with a plurality of first annulars on the oil blanket body, be equipped with the second annular that corresponds with first annular on the main shaft, the second annular forms labyrinth seals with the cooperation of first annular, be equipped with radial oil gallery on the first annular, on personally experiencing sth. Part of the body, the oil blanket is equipped with the axial oil gallery that communicates with radial oil gallery, still including the independence time oil pipe way that is located the casing, independent return the oil pipe way include with the entrance point of axial oil gallery intercommunication and with the exit end of the inside intercommunication of casing, the pressure of entrance point is greater than the pressure of exit end, pressure differential between entrance point and the exit end is more than or equal to atmospheric pressure difference value between the inside of first annular and casing. It still has better sealed effect in the time of being greater than the annular atmospheric pressure of the oil blanket body at the inside atmospheric pressure of casing.