The invention discloses a process for manufacturing piston rings by cylindrical ellipse blanks, comprising a blank casting procedure and a blank slicing procedure, wherein the casted blank is an elliptical cylindrical body the length of which is equal to the sum of the thicknesses of multiple single piston rings. In the slicing procedure, the whole cylindrical body blanks are processed completelyat one time by row of knives; when in feeding the knife, a cam alongside mould is adopted to feed the knife elliptically; and a transitional soft lining which is manufactured by nonmetallic materialsis arranged between the inner bore of the blank and an expansion tyre, so as to prevent the inner tyre and the expansion tyre from sliding relatively. By the process in the invention, the production cost of the piston rings can be reduced, the production efficiency is improved, the processing advantages of the process of the original elliptical monomer and binary body can be kept, and the processcan be applied widely in the same industries.