The invention relates to a production method of a quenched and tempered high-strength Q500D super-thick steel plate. The process steps are as follows: pretreatment of molten iron, steel-making by a converter, secondary refining, continuous casting (dynamic soft reduction and electromagnetic stirring), heating, rolling, pre-straightening, online quenching, offline quenching, tempering, finishing, performance testing and ultrasonic flaw detection. Steel comprises the following chemical components in percentage by weight: not more than 0.15% of C, 0.20-0.40% of Si, 1.00-1.30% of Mn, not more than 0.015% of P, not more than 0.003% of S, 0.03-0.06% of AlT, not more than 0.10% of Nb+Ti+V, not more than 1.0% of Cu+Ni, 0.40-0.70% of Cr, 0.30-0.60% of Mo, not more than 0.0025% of B and the balance of Fe and inevitable impurities. The CEV (carbon equivalent) is controlled to be not more than 0.58, and the CEV is calculated according to the following formula: CEV=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15. The produced high-performance 100-120mm quenched and tempered high-strength Q500D super-thick steel plate can meet the needs for manufacturing heavy machinery in mines, ports and the like.