The invention relates to a super wear-resistant cast steel grinding ball and a preparation method thereof. The grinding ball is made of the following chemical components in weight percent: C: 0.80-1.10, Si: 0.40-1.20, Mn: 0.50-1.00, Cr: 6.50~8.50, Ti: 0.15~0.20, Re: 0.02~0.03, P<0.03, S<0.03, the balance is Fe; its preparation method adopts mechanized lost foam casting, the casting is heated and kept warm, oil quenched, and then The finished product can be obtained after tempering, which can realize the mechanized mass production of grinding balls, greatly improve production efficiency, reduce labor intensity, and realize clean production. The super wear-resistant cast steel grinding ball prepared by the invention has higher wear resistance, Rockwell hardness and impact toughness than the existing Cr12 high-chromium cast iron grinding ball. The super wear-resistant cast steel grinding ball of the present invention can be used as a wear-resistant material in cement, thermal power, ore dressing and other industries for powder processing.