690MPa-grade steel plate with excellent low-temperature ductility and manufacturing method

The invention provides a 690 MPa grade steel plate with excellent low-temperature ductility and a manufacturing method. The steel plate comprises the following components in percentage by weight: 0.100%-0.180% of C, 0.15%-0.75% of Si, 0.80%-1.60% of Mn, 0.060%-0.200% of V, 0.40%-0.80% of Cu, 2.50%-3.50% of Ni, 0.80%-1.80% of Cr, 0.60%-1.60% of Mo, 0.020%-0.070% of La, 0.0020%-0.0040% of B, less than or equal to 0.008% of P, less than or equal to 0.003% of S and the balance of Fe and inevitable impurities. The manufacturing method comprises the steps of smelting, continuous casting, casting blank cooling, heating in a heating furnace, rolling, cooling and tempering. The tensile properties of the steel plate at-40 DEG C are as follows: the yield strength is 750MPa or above, the tensile strength is 840MPa or above, and the percentage elongation after fracture is 23.0% or above. The impact energy of the steel plate at-80 DEG C is greater than 200J, the ductile-brittle transition temperature FATT is less than-75 D