The invention discloses a seawater corrosion resistant steel plate with high crack arrest and strain aging embrittlement resistance characteristics and a manufacturing method thereof. The seawater corrosion resistant steel plate is prepared from the compositions in percentage by weight: 0.040-0.070% of C, less than or equal to 0.15% of Si, 0.85-1.15% of Mn, less than or equal to 0.013% of P, lessthan or equal to 0.0030% of S, 0.90-1.20% of Cu, 0.60-1.00% of Ni, 0.05-0.30% of Mo, 0.010-0.030% of Nb, 0.008-0.014% of Ti, 0.040-0.070% of Al, less than or equal to 0.0050% of N, less than or equalto 0.0003% of B, 0.0010-0.0040% of Ca and the balance of Fe and inevitable impurities. The steel plate has high strength, excellent low-temperature toughness, the crack arresting characteristic and the strain aging embrittlement resistance characteristic, further has excellent seawater corrosion resistance, can withstand large heat input welding, is particularly suitable for icebreaker shells, offshore platforms, sea-crossing bridges, ocean wind tower structures, hydroelectric metal structures (pressure steel pipes, volutes, steel bifurcated pipes and hydraulic turbine metal components), pressure vessels and the like in ice sea areas, and can achieve stable mass industrial production.