The invention relates to a rotary compressor, which comprises a motor assembly and a pump assembly, wherein the motor assembly and the pump assembly are arranged inside a housing, and the motor assembly is arranged above the pump assembly. The motor assembly comprises a stator and a rotor. The pump assembly comprises a cylinder, an elliptical piston arranged inside the cylinder, slide sheets arranged inside cylinder slide sheet grooves, a rotation shaft for driving the elliptical piston to rotate, a main bearing and a sub-bearing, wherein the main bearing and the sub-bearing are arranged on an upper side and a lower side of the cylinder. A center line of the elliptical piston and a center line of the cylinder cavity are overlapped. The two slide sheet grooves are arranged, each slide sheet groove is provided with the slide sheet, and one end of the slide sheet contacts the outer periphery of the elliptical piston. During compressor operation, the end portion of the slide sheet is tightly close to the outer periphery of the elliptical piston. The rotary compressor of the present invention has characteristics of simple and reasonable structure, smooth and reliable operation, and low vibration noise.