Innovations were made in the design of core nozzle, the configuration of quenching zone, the removal of residual water, the quenching technology and the quenching strategy according to the problems in current quenching production of ultra- heavy plate. The first ultra- heavy plate roller quenching machine in the world was successfully developed in Wugang. The effect of cooling rate and temperature gradient on cross- section effect was studied by measuring the temperature drop curves and microstructure properties at different locations during quenching of ultra- heavy steel plate. The industrial verification shows that the ultra- heavy plate roller quenching machine surpasses the tank quenching machine in terms of temperature uniformity, surface quality, quenching shape and performance.