Extra-thick hull and offshore platform heavy steel plate use component design of low carbon content and Nb-Ni-Ti composite, LF + VD refining, and use the technology of rough rolling at high temperature  and heavy rolling reduction ratee and TMCP controlled rolling and controlled cooling, which has successfully achieved the structure transformation of high strength shipbuilding steel plate from ferrite , pearlite to composition of fine acicular ferrite and semi-polygonal ferrite and ultimately have achieved high strength, high toughness, low-cost, energy-efficient  properties,  and can meet comprehensive performance requirements of Extra-thick F36Z35 steels.