The invention discloses a bias lining type wear resistant dust and gas butterfly valve which comprises a valve body, wherein the valve body is internally provided with a valve shaft, and a disc is arranged on the valve shaft in the valve body; the disc consists of a disc small circle side and a disc large circuit side; the valve body is internally and fixedly provided with a semi-circular wear resistant lining plate mutually matched with the inner wall of the valve body; the inner wall of the semi-circular wear resistant lining plate and the inner wall at one side of the valve body are respectively and fixedly provided with a first valve seat and a second valve seat; the disc small circle side and the disc large circuit side of the disc are respectively and mutually matched with the firstvalve seat and the second valve seat; a first gap is reserved between the end part of the disc small circle side of the disc and the inner wall of the semi-circular wear resistant lining plate; and asecond gap is reserved between the end part of the disc large circuit side and the inner wall of the valve body. The invention has the advantages that the structure is simple, and an asymmetrical disc and asymmetrical valve body structure is adopted to replace a traditional universal symmetrical structure; material layouts are reasonable, thus cost is saved, and the service life of the valve bodyis prolonged; an original sealing property is not changed; and the process is simple and easy to apply.