Thrust cylindrical roller bearing has a character of sell-aligning because the center of its raceway profile right fall on the center line of its bore diameter, even the shaft are bending slightly or the housing are inclining slightly, these errors of alignment cannot make the center of its raceway profile leave the center line of its bore diameter, this means the bearing can self-align, thus cannot produce other kinds of unnecessary strengths due to wrong alignment of shaft relative to housing. The cylindrical roller bearings are processed by convexity, so the pressure between roller and raceway sureface is easily distributed. This type of bearing is provided with separable structures, and blowout parch, seat ring and roller bodycomponent which can be easily mounted and dismounted. During the mounted, the shaft is not allowed to incline relative to the housing axis.