The invention provides steel with high impact strength and a casting prepared from the steel. The steel is characterized in that the steel includes the following components by weight: 0.26 to 0.29 percent of C (carbon), 0.20 to 0.40 percent of Si (silicon), 1.40 to 1.60 percent of Mn (manganese), 0.60 to 0.70 percent of Cr (chromium), 0.55 to 0.75 percent of Ni (nickel), 0.30 to 0.35 percent of Mo (molybdenum), 0.02 to 0.05 percent of Al (aluminum), no more than 0.30 percent of Cu (copper), no more than 0.015 percent of P (phosphorus), no more than 0.015 percent of S (sulfur), and the balance of iron and other unavoidable elements. The invention further provides the casting which is prepared from the steel with the high impact strength through casting and heat treatment. The steel with the high impact strength provided by the invention can meet the requirements of new standards, and has a higher impact energy indicator.