Abstract: Through the design composition (/% : 0. 09C, 0. 15Si, 1. 15Mn, 0. 58Ni, 0. 47Cr, 0. 44Mo,0. 033V, 0.022Nb,0.0012B,0.036Al,0.014Ti) , the N content of smelting analysis controlled to be ≤ 20 x 10^-6 in steel smelting, rolling with ingot maximum heating temperature ≤1 200 °C , and quenching at 930 °C and tempering at 610 °C,the developed 60 mm SX780CF steel plate has yield strength 780 MPa, tensile strength 887 MPa, elongation 18% and 5% strain 250 °C aged -20 °C impact energy (KV₂) 203 ~ 210 J, which meet the technical requirements of 800 MPa low welding crack sensitivity high strength steel for hydropower station.