At present, an ultra-fast cooling technology is mainly applied to cooling of steel after two-stage controlled rolling. The invention discloses an optimal controlled rolling method adopting ultra-fast cooling to control an Austenite structure and belongs to the technical field of metallurgy. According to the method, the steel can be completely rolled in a steel billet Austenite recrystallization zone, rolling temperature and pass reduction rate can be simultaneously precisely controlled, an ultra-fast cooling system is immediately adopted to cool the rolled steel to a phase transition point after rolling, and then different cooling paths are adopted according to needs to control the phase transition of the steel. According to the method disclosed by the invention, the ultra-fast cooling is adopted, so that coarsening of the small re-crystallized Austenite structure can be effectively inhibited, and the refining effects of dynamic recrystallization and sub-dynamic recrystallization against the Austenite structure in a high-temperature rolling process can be retained. The product manufactured by the method disclosed by the invention and the steel manufactured by the two-stage controlled rolling process have equivalent mechanical properties, so that the rolling time is simultaneously reduced by 2-4min in comparison with the two-stage controlled rolling process at a waiting temperature and low-temperature atmosphere in the rolling process.