A high tempering parameter PWHT embrittlement resistant, extra thick cryogenic steel plate and a manufacture method thereof. The steel plate comprises, by weight, 0.030%-0.070% of C, Si no more than 0.15%, 1.30%-1.60% of Mn, P no more than 0.013%, S no more than 0.0025%, 0.040%-0.070% of Als, 0.10%-0.40% of Cu, 0.25-0.65% of Ni, 0.10%-0.30% of Cr, 0.05%-0.25% of Mo, 0.007%-0.013% of Ti, 0.010%-0.030% of Nb, 0.020%-0.050% of V, N no more than 0.0045%, 0.001%-0.004% of Ca, residual iron and unavoidable inclusions. According to optimized controlled rolling and two times of normalizing technology, the steel plate gains extremely high ultralow temperature toughness, excellent HIC / SCC resistance, weldability and bearing capacity of high heat input welding; and more importantly, the steel plate has excellent high tempering parameter PWHT embrittlement resistance characteristic, and is especially suitable for manufacture of large-scale LPG low temperature storage tank, low temperature storage tank for ship and ocean platform for ice ocean.