The invention discloses a manufacturing method for an oil pump rotor, and belongs to the technical field of oil pump parts. The manufacturing method includes the steps of mixing, blank pressing, pre-combusting, re-pressing, sintering, shaping, tempering, secondary shaping and heat treating, and finally finished products with the final density greater than or equal to 7.2 g / cm<3> and the rigidity greater than or equal to HRC40 can be obtained. According to the manufacturing method, the cycloidal rotor is produced through the powder metallurgy pressing method, mass production can be realized, the production efficiency is high, the product stability is good, and the material utilization rate is high. The density of the produced cycloidal rotor can reach 7.2 g / cm<3> which cannot be realized through common powder metallurgy methods; the product rigidity can reach HRC40 or above after quenching, the abrasion resistance is good, and the service life is greatly prolonged; and the material utilization rate is increased, the machining difficulty is lowered, the production efficiency is improved, and the product stability is improved.