An embodiment of the invention discloses a rotary compressor. The rotary compressor comprises a main bearing, a secondary bearing, a cylinder and a crankshaft, wherein the main bearing and the secondary bearing are arranged on the crankshaft and are positioned at two ends of the cylinder; a part, which is in contact with the main bearing and the secondary bearing, of the cylinder is an oil pool; a first oil guiding groove, a second oil guiding groove, a first oil inlet and a first oil returning opening are formed in the inner wall of the main bearing; the first oil guiding groove communicates with the second oil guiding groove; the first oil inlet communicates with the first oil guiding groove and the oil pool; and the first oil returning opening communicates with the second oil guiding groove and the oil pool. Lubricating oil enters the first oil guiding groove from the first oil inlet, a part of lubricating oil passes through the second oil guiding groove and finally returns to the oil pool through the first oil returning opening, and the other part of lubricating oil continues lubricating the crankshaft and the main bearing via the first oil guiding groove, so that a circulating oil line is formed. The actual quantity of the lubricating oil flowing in and flowing out of the main bearing is reduced, and requirements on oil supply amount are reduced. Particularly, under the condition of oil starvation, good lubrication can still be implemented. The invention further discloses an air conditioner.