The invention discloses steel for a high-strength, high-toughness and high-wear-resistance steel ball and a preparing method of the steel, and belongs to the technical field of steel for wear-resistant steel balls. The problems that the strength and toughness of existing steel for wear-resistant steel balls cannot meet requirements at the same time, and uniformity is poor are solved. The steel forthe wear-resistant steel ball comprises, by mass, 0.60-0.70% of C, 1.50-1.80% of Si, 0.92-1.2% of Mn, 1.30-2.00% of Cr, 0.01-0.20% of Mo, 0.25-0.60% of Ni, 0.01-0.05% of Al, 0.05-0.10% of Cu, 0.01-0.20% of V, less than or equal to 0.03% of S, 0.01-0.02% of P and the balance Fe and inevitable trace impurities, wherein the sum of Mo and V is greater than or equal to 0.08%. The preparing method includes the following steps of performing smelting to obtain molten steel, performing casting to obtain a cast ingot, forging the cast ingot to obtain a steel blank, and performing quenching and annealing treatment on the steel blank or quenching and partitioning treatment on the steel blank. The steel for the high-strength, high-toughness and high-wear-resistance steel ball is high in strength, toughness and uniformity and wide in application range.