The invention relates to the technical field of ore grinding medium addition for large ball mills, in particular to a novel method for proportioning ore grinding media, which comprises the following steps of: (1) making regulations on composition of feed granularities for a ball mill; (2) adding two ore grinding media different in diameter at the same time according to the regulated composition of feed granularities; (3) keeping two ore grinding media different in diameter in proportion by weight of 1: (0.9-1.1); (4) keeping the filling ratio of the ore grinding media for the ball mill at 38-42%; and (5) determining the adding quantity and the adding cycle of the ore grinding media in each time according to the effective volume of the ball mill, wherein the ore grinding media are steel balls, the adding cycle of the ore grinding media respectively is 24h, 12h, 8h, 4h, or 2h, and the steel ball is 127mm, 120mm, 110mm, 100mm or 80mm in diameter. The method for proportioning the ore grinding media has the beneficial effects that the yield of coarse grade products is reduced, the yield of fine grade products is increased, the ore grinding efficiency of the ball mill is improved, and the composition of ore grinding granularities is improved at certain degree to satisfy the requirement of follow-up grading work.