High strength weld joint with improved high heat input toughness

In this specification, a high strength welded joint having improved high heat input toughness by controlling the microstructure is disclosed. According to one embodiment of the present invention, the high strength weld joint with improved high heat input toughness may comprise: in weight percent (wt.%); at least 0.03% but not more than 0.045% of C, at least 1.45% but not more than 1.55% of Mn, at least 0.3% but not more than 0.4% of Si, at least 0.02% but not more than 0.03% of Al, at least 1.55% but not more than 1.70% of Ni, at least 0.05% but not more than 0.07% of Cr, at least 0.05% but not more than 0.08% of Cu, at least 0.14% but not more than 0.2% of Mo, at least 0.06% but not more than 0.07% of Ti, at least 0.004% but not more than 0.005% of Nb, at least 0.035% but not more than 0.05% of O, at least 40 ppm but not more than 180 ppm of N, greater than 0 ppm but not more than 80 ppm of P, greater than 0 ppm but not more than 90 ppm of S, and the balance of iron (Fe) and other unavoidable impurities. 在本说