Production method for improving strength and toughness of extra-thick steel plate based on TMCP process

The invention relates to a production method for improving the strength and toughness of an extra-thick steel plate based on a TMCP process. The production method comprises the steps that a continuouscasting slab with the composition meeting the requirements is reheated, and then a qualified product is directly produced through a controlled rolling and controlled cooling process. The reasonable combination of strength and toughness is comprehensively considered on the aspects of rolling and cooling schedule optimization, the original austenite grain size is fully refined, the austenite deformation accumulation is increased, and a reasonable cooling system is adopted to ensure that the proportion of the structure is constant, so that the technological potential of modern material processing is fully reflected, the effect of phase change control technological means such as controlled rolling and controlled cooling on the improvement of strengthening and toughening of steel is brought into play, and the high fra