The invention discloses a method for controlling the size uniformity of hot rolled high-carbon austenitic stainless steel grains. The method comprises the following steps: 1, preparing a high-carbon austenitic stainless steel hot rolled medium plate; 2, putting the medium plate in a heating furnace of 900-920 DEG C for preheating, wherein the preheating time t1 is equal to 0.4-0.6 hour; 3, raisingthe temperature of the preheated plate to 1000-1010 DEG C along with the furnace for recrystallization treatment, or taking the preheated plate out for slow cooling, warming the heating furnace to 1000-1010 DEG C, and then putting the preheated plate in the heating furnace for recrystallization treatment; 4, raising the temperature of the recrystallization plate by 50-100 DEG C along with the furnace for solution treatment, or taking the recrystallization plate out for slow cooling, raising the temperature of the heating furnace by 50-90 DEG C, and then putting the recrystallization plate inthe heating furnace for solution treatment; and 5, carrying out water quenching on a solid solution plate to the normal temperature. According to the method, the recrystallization kinetics and the thermodynamics are taken as the acting points, the multi-stage stepped type annealing technology is adopted to release deformation stored energy step by step, the medium plate with uniform grains and adjustable and controllable grain size is obtained, the maneuverability is high, and industrial application can be realized.