The invention relates to a cleaning device of a draft beer barrel, and belongs to the technical field of cleaning equipment. The cleaning device comprises a pedestal, a mounting seat, a buffer, a support, a connection rod, a cylinder I, a cylinder II, a supporting rod, a movable block, a catching device, a water feeding pipe, a rotatable joint, a central pipe, a driving device, a cleaning device and a disk brush. The cleaning device of the draft beer barrel is simple in structure and convenient to maintain; automatic catching and cleaning of the draft beer barrel can be realized, the automation degree is greatly increased, the labor cost is reduced, and the safety and the cleaning efficiency are improved; meanwhile, a more advanced cavitating jet technology is used, and the water use amount is extremely small; and after bubbles formed by water flow are broken, locally high impact pressure and stress are concentrated, and the cleaning effect is extremely good.