Abstract: A bearing detachment device has a main panel, a pneumatic cylinder, a plurality of support rods, a plurality of catch plates, a fast positioning device, a plurality of oblong blocks, a plurality of connecting bars, and a cylindrical block. The main panel has a center hole to receive the pneumatic cylinder, a plurality of lugs, and a plurality of bottom grooves. Each support rod has a threaded pillar inserted in the oblong block. Each oblong block is inserted in the corresponding bottom groove. Each catch plate has two end claws. Each connecting bar is inserted in the corresponding lug. Each connecting bar and the corresponding lug are fastened together. Each connecting bar and the corresponding catch plate are fastened together. The fast positioning device is disposed on the main panel. The cylindrical block has an oblong groove and a threaded column to engage with an end block of the pneumatic cylinder.