Disclosed herein is an apparatus and method for forming a product having an asymmetric cross-section using a ring rolling process. The method of forming a product having an asymmetric cross-section uses a ring rolling process that uses a ring rolling apparatus, the ring rolling apparatus comprising: a main roll pressing a circumferential outer surface of a blank, a pressure roll pressing a circumferential inner surface of the blank, and a pair of axial rolls pressing upper and lower surfaces of the blank, wherein a protrusion provided on the pressure roll comes into contact with a depressed portion formed on the circumferential inner surface of the blank, and as a width of the blank varies, the pressure roll moves in a vertical direction.