Thick steel plate with great line energy and low welding crack sensitivity and its production process

The present invention discloses one kind of thick steel plate with great line energy and low welding crack sensitivity and its production process. The chemical composition includes C 0.06-0.10 wt%, Si 0.15-0.40 wt%, Mn 1.20-1.60 wt%, P not more than 0.015 wt%, S not more than 0.007 wt%, Ni 0.15-0.40 wt%, Cr not more than 0.30 wt%, Mo 0.15-0.30 wt%, V 0.02-0.06 wt%, Al 0.015-0.045 wt%, Ti 0.010-0.034 wt%, except Fe and inevitable impurities; and meets Pcm not higher than 0.20 %. The production process includes pre-treatment of molten iron, smelting in converter, LF furnace plus VD furnace vacuum treatment, two stage controlled rolling, on-line laminar flow cooling, tempering at 600-680 deg.c and other steps. The produced steel plate has no need of quenching and tempering treatment.