The invention relates to an oil lubricating bearing. The oil lubricating bearing comprises an inner ring and an outer ring, wherein roller grooves are formed in the inner ring and the outer ring; rollers are arranged in the roller grooves; an oil inlet is formed in the inner ring or the outer ring; an oil discharge hole is formed in the bottom of the outer ring; an oil return sealing ring is assembled on the outer ring in a sealing mode; one side, towards the rollers, of the oil return sealing ring is equipped with a ring-shaped oil return slot for collecting lubricating oil which is thrown out from the roller grooves; a ring-shaped guide surface positioned between the roller grooves and the oil return sealing ring is arranged on the inner ring; and the radius of the portion, close to theoil return sealing ring, of the ring-shaped guide surface is not smaller than that of a slot hole of the ring-shaped oil return slot. According to the oil lubricating bearing disclosed by the invention, lubricating oil is input through the oil inlet, so that high-speed performances of the bearing can be guaranteed for bearing lubrication; and lubricating oil which is thrown out from the roller grooves quickly returns the ring-shaped oil return slot of the oil return sealing ring under guide of the ring-shaped guide surface, so that heat dissipation efficiency of the bearing is improved, and lubricating oil is guaranteed to not leak outsides.