The invention discloses a large-diameter forged wear-resisting steel ball special for a mine and a preparation method thereof and relates to the technical field of wear-resisting materials. The chemical components of the large-diameter forged wear-resisting steel ball special for the mine comprise, by weight, 0.8-1.2% of C, 0.6-0.9% of Si, 1.2-1.5% of Mn, 1.0-1.5% of Cr, 0.1-0.3% of Mo, 0.05-0.15%of V, 0.1-0.2% of Ti, 0.05-0.15% of Al, 0.05-0.15% of Cu, 0.05-0.15% of Zr, 0.05-0.15% of Hf, 0.08-0.2% of B, 0-0.02% of P, 0-0.01% of S, and the balance Fe and inevitable impurities. The preparationmethod comprises the steps of smelting, forging and heat treatment. The chemical components and contents thereof of the large-diameter forged wear-resisting steel ball special for the mine are reasonably optimized, stability of the undercooled austenite and hardenability of steel can be improved through the added hardening elements like Mn, Mo, Cr, V, Ti and Cu, the difference value of the core portion hardness and the surface hardness of the large-diameter wear-resisting steel ball is reduced, the prepared wear-resisting steel ball is smooth and defect-free in surface, high in hardness, goodin toughness and not prone to being broken, the performance of the prepared wear-resisting steel ball can be comparable with high-chromium grinding balls, the prepared wear-resisting steel ball can replace casting balls to be used for ore wet grinding, and the ore grinding efficiency is improved.