Steel plate having high strength and excellent low-temperature impact toughness and method for manufacturing thereof

Provided are high strength steel having excellent low-temperature impact toughness, and a method for manufacturing same. The high strength steel having excellent low-temperature impact toughness of the present invention comprises, in percentage by weight: 0.04-0.12% of carbon (C); 0.1-0.5% of silicon (Si); 1.2-2.5% of manganese (Mn); 0.01% or less of phosphorus (P); 0.01% or less of sulfur (S); 0.01-0.08% of aluminum (Al); 0.01-0.08% or less of niobium (Nb); 0.01-0.5% of chromium (Cr); 0.4-1.0% of nickel (Ni); 0.5% or less of copper (Cu); 0.01-0.5% of molybdenum (Mo); 0.05% or less of vanadium (V); 0.005-0.02% of titanium (Ti); 0.001-0.0025% or less of boron (B); 0.002-0.01% of nitrogen (N); and the balance being Fe and inevitable impurities, wherein the high strength steel has a Ceq value less than 0.55 represented by relational expression 1 below, has an internal microstructure consisting of 80% or more of bainitic ferrite and balance granular bainite in an area fraction at a point of 1/4t of the thickness thereof, and has an aspect ratio of a prior austenite grain boundary of 3.0 or greater and a thickness of 60 mm or greater and 100 mm or less.