Heavy steel plate flatness controlling method

The invention discloses a method for controlling the planeness of a thick steel plate, which comprises the following steps: (1) heating process, during which the height of the hearth bottom is guaranteed to accord with the requirement of the prescription; meanwhile, the heating temperature of steel ingot and proximate matter is even so that the steel ingot and the proximate matter are burnt; (2) rolling process, during which a steel plate is transversely placed, and the upper surface temperature and the lower surface temperature of the steel plate are even so as to prevent the steel plate from upwarping or buckling downwards; (3) leveling a roll table, during which the height difference between a lower working roller and a front breast roll and a rear breast roll is adjusted so that the lower working roller is higher than the front breast roll and the rear breast roll by 0 to 35 mm; and (4) matching the rolling speed with the operation speed of the roll table in the rolling process. The method of the inventio