The invention provides a tapered roller bearing assembling machine. The tapered roller bearing assembling machine comprises a work table top, an operating mechanism, a retainer feeding mechanism, a retainer pushing mechanism, a position detecting mechanism, a roller and inner ring assembling mechanism, a roller assembling detecting mechanism, an assembling body orientation mechanism and a rivetingmechanism; the work table top comprises a retainer feeding station, a retainer pushing station, a position detecting station, a roller and inner ring assembling station, a roller assembling detectingstation, an assembling body orientation station and a riveting station; and the operating mechanism is used for transporting assembling bodies to the next station, the retainer feeding mechanism is used for feeding retainers, the retainer pushing mechanism is used for pushing the retainers, the position detecting mechanism is used for detecting whether the retainers are located at the center of the position detecting station or not, the roller and inner ring assembling mechanism is used for assembling rollers into holding frames, the roller assembling detecting mechanism is used for detectingwhether the large ends and the small ends of the rollers in the holding frames are assembled correctly or are complete or not, the assembling body orientation mechanism is used for orientating the assembling bodies, and the riveting mechanism is used for riveting the assembling bodies. Through all the mechanisms and stations in the tapered roller bearing assembling machine, fully-automatic assembling of tapered roller bearings can be achieved, and the assembling efficiency and the assembling quality are improved.