Under the condition of high temperature, excess moisture and heavy load , the main damaged pattern of drying cylinder bearings of high speed paper machi ne is their inner race surface peeling in the rolling path. With the increase of the inner race surface peeling, the drying cylinder bearings’ vibrations rise. The fault frequency in the vibration frequency spectrum shifts from the high fr equency band to the low frequency band, and the shaft speed sidebands by both si des of fault frequency increase and heighten gradually. In the case of outer rac e’s rupture of drying cylinder bearings, the whole band of vibrating frequency spectrum will feature the speed frequency’s loose characteristics.