The invention discloses a production method for alleviating transverse bends of a thick-specification cold-rolled plate. According to a cover annealing procedure, inner stress of strip steel is fully released by prolonging heat preservation time of cover annealing and reducing cooling speed; transverse performance of the plate surface and inner stress of the steel plate are homogenized; and raw material preparation is made for a flattening procedure. According to the flattening procedure, a positive convexity roll and a negative convexity roll are adopted as an upper work roll and a lower work roll correspondingly; roll gaps bent upward are formed in the flattening process; a plate strip tends to be bent upward; and the pressure difference, in the thickness direction, of the plate strip is balanced. According to a rewinding procedure, straightening is conducted through a rewound wire straightening machine; and the stress deviation problem in the thickness direction and the width direction is improved. By means of the production method for alleviating the transverse bends of the thick-specification cold-rolled plate, the transverse bend problem of the thick-specification cold-rolled plate is effectively improved; for the cold-rolled plate with transverse bends ranging from 40mm to 70mm before the cold-rolled plate is flattened, the transverse bends are generally smaller than 15mm after the cold-rolled plate is flattened and straightened; flatness and straightness requirements for cold-rolled carbon steel plates as specified in Japanese standards are met completely; the transverse bend problem of the thick-specification cold-rolled plate is alleviated; and the first-grade product ratio of the thick-specification cold-rolled plate is increased.