This invention relates to a method for producing high-strength ship plate steel suitable for high heat input welding. The chemical compositions of the ship plate steel are: C 0.01-0.18 wt.%, Si 0.05-0.4 wt.%, Mn 1.0-1.8 wt.%, Als 0.001-0.06 wt.%, Nb 0.01-0.08 wt.%, Ti 0.01-0.08 wt.%, N 0.002-0.012 wt.%, B 0.0001-0.0030 wt.%, one or more of Ca, Mg and Zr 0.0001-0.030 wt.%, P less than 0.015 wt.%, S less than 0.010 wt.%, Fe and impurities. The method comprises: keeping the oxygen content in the molten steel at 10-600 ppm, performing deoxidation with Fe-Ti alloy or metal Ti after steelmaking, adding one or more of Ca, Mg and Zr, performing final deoxidation with Al wire, adding B, casting, homogenizing, rolling, relaxing, and cooling online. The obtained ship plate steel has such advantages as simple chemical compositions, simple process, and high heat input welding, and is suitable for producing ships.