S460G2+QT steel plate for fixed offshore platform and production method of steel plate

The invention discloses an S460G2+QT steel plate for a fixed offshore platform and a production method of the steel plate. The production method comprises the following process steps: smelting, continuous casting, heating, rolling, cooling, quenching and tempering, wherein the continuous casting billet obtained in the continuous casting process comprises the following chemical components in percentage by mass: 0.08-0.10 percent of C, 0.20-0.50 percent of Si, 1.40-1.50 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.005 percent of S, 0.15-0.20 percent of Cr, less than or equal to 0.25 percent of Mo, 0.30-0.35 percent of Ni, 0.020-0.045 percent of Al, less than or equal to 0.10 percent of Cu, less than or equal to 0.008 percent of N, 0.035-0.040 percent of Nb, less than or equal to 0.025 percent of Ti, 0.040-0.050 percent of V and the balance of Fe and inevitable residual elements and impurities. According to the method, low-cost chemical components and a quenching and tempering process with low energy and time consumption are adopted, so that the S460G2+QT steel plate with the advantages of high strength, high toughness, fatigue resistance, lamination crack resistance and excellent weldability is produced.