The invention discloses a rotation preventing bolt gasket. A special-shaped piece (1) and a special-shaped piece (2) are included. The special-shaped piece (1) is in threaded connection with a fixingbolt, the fixing bolt is in threaded connection with a fixing nut, the outer portion of the fixing bolt is in cup joint with a rotation preventing gasket, and the fixing nut is located in the rotationpreventing gasket. The rotation preventing bolt gasket is adopted, particularly in the narrow installing place, when a wrench tool cannot be used, the rotation preventing bolt gasket is directly adopted, the situation that the wrench tool is used at the two ends for clamping a nut and a bolt is avoided, and the bolt is directly tightened only by using the wrench tool at one end. Accordingly, theinstalling efficiency is greatly improved, and the installing cost is saved.