The invention discloses a manufacturing method of a precise tapered roller specially for a high speed train unit. The manufacturing method comprises the processes of high-speed multistation cold-forging molding, hot acid pickling, stress-relieving annealing, pre-cleaning, quenching treatment, low-temperature cold treatment, first tempering, grinding, magnetic powder inspection, superfinishing, cleaning, finished product appearance inspection, size sorting, spot checking for surface quality, oiling, counting and packaging. The high-speed multistation cold-forging molding process is adopted to realize direct heat treatment on a forged piece, the incomplete quenching process is adopted to carry out hot quenching treatment under the protection of controllable atmosphere, low-temperature cold treatment is carried out immediately after quenching treatment, after the temperature of a steel ball after cold treatment is restored to be at room temperature, the first tempering treatment is carried out, a ball grinding cardinal plane during grinding is in a non-magnetic mode, and all related processes of grinding processing after quenching can be carried out one time. By adopting the manufacturing method, the service life of a roller can be prolonged, the material consumption and the production cost are reduced, the quality of a roller blank is improved, the processing flows of the roller are reduced and the production efficiency is improved.