550MPa-grade steel plate with excellent low-temperature ductility and manufacturing method of 550MPa-grade steel plate

The invention relates to a 550MPa-grade steel plate with excellent low-temperature ductility and a manufacturing method of the 550MPa-grade steel plate. The steel plate comprises the following chemical components: 0.040%-0.120% of C, 0.20%-0.70% of Si, 1.00%-1.40% of Mn, 0.010%-0.050% of Nb, 0.020%-0.080% of V, 0.30%-0.70% of Cu, 0.0120%-0.0160% of N, 0.60%-1.20% of Ni, 0.60%-1.20% of Cr, 0.30%-0.60% of Mo, 0.010%-0.035% of La, less than or equal to 0.008% of P, less than or equal to 0.003% of S and the balance of Fe and impurities. The strength, low-temperature toughness and ductility of the steel are improved through chemical component design; a high-superheat-degree strong secondary cooling water process is adopted for continuous casting, the proportion of columnar crystals of a continuous casting billet is controlled to be larger than 96%, internal stress caused by strong cooling is reduced through stacking slow cooling, and meanwhile the grain size of the continuous casting billet is controlled; a segmen