The invention relates to high-performance marine mooring chain steel and a manufacturing method thereof. The method comprises the following steps: a. tapping compositions comprise the following by weiThe invention relates to high-performance marine mooring chain steel and a manufacturing method thereof. The method comprises the following steps: a. tapping compositions comprise the following by weight percentage: C: 0.16 to 0.27, Mn: 0.40 to 1.45, Si: 0.15 to 0.50, Cr: 1.25 to 2.50, Ni: larger than 0 and less than 1.20, Mo: 0.20 to 0.60, Al: 0.01 to 0.06, N: 0.004 to 0.015, S: not larger than 0ght percentage: C: 0.16 to 0.27, Mn: 0.40 to 1.45, Si: 0.15 to 0.50, Cr: 1.25 to 2.50, Ni: larger than 0 and less than 1.20, Mo: 0.20 to 0.60, Al: 0.01 to 0.06, N: 0.004 to 0.015, S: not larger than 0.005, P: not larger than 0.015, Cu: larger than 0 and less than 0.50, and the balance of Fe; b. a steel ingot or a continuous casting billet is casted after the steps of primary smelting in an electri.005, P: not larger than 0.015, Cu: larger than 0 and less than 0.50, and the balance of Fe; b. a steel ingot or a continuous casting billet is casted after the steps of primary smelting in an electric stove or a converter, external refining and vacuum degassing; c. the charging temperature of a heating oven is not larger than 900 DEG C, the heating rate is not larger than 150 DEG C / h; when beingc stove or a converter, external refining and vacuum degassing; c. the charging temperature of a heating oven is not larger than 900 DEG C, the heating rate is not larger than 150 DEG C / h; when beingraised to 1100 to 1300 DEG C, the temperature is kept for more than 40 minutes, cogging bloom or rolling by a finisher is carried out, and the finishing temperature is not larger than 1050 DEG C; andraised to 1100 to 1300 DEG C, the temperature is kept for more than 40 minutes, cogging bloom or rolling by a finisher is carried out, and the finishing temperature is not larger than 1050 DEG C; andd. after heated at the temperature of 1000 to 1250 DEG C, the cogged ingot is hot-rolled or forged into round steel, the finishing temperature is not larger than 1050 DEG C, and after rolling, the sted. after heated at the temperature of 1000 to 1250 DEG C, the cogged ingot is hot-rolled or forged into round steel, the finishing temperature is not larger than 1050 DEG C, and after rolling, the steel is air-cooled, slow cooled or softening heat-treated at the temperature of not less than 600 DEG C. The performance of finished products achieves or exceeds the requirement of level 4.5 and level 5el is air-cooled, slow cooled or softening heat-treated at the temperature of not less than 600 DEG C. The performance of finished products achieves or exceeds the requirement of level 4.5 and level 5 of mooring chain steel.of mooring chain steel.