The invention discloses a correction method of a wide and thick plate camber, and belongs to the technical field of rolling. The correction method of the wide and thick plate camber comprises the steps that line formation industrial cameras are installed at the upper portion of a front roller way of a rolling mill and the upper portion of a rear roller way of the rolling mill, steel plate images at the position of an outlet of the rolling mill are obtained through the line formation industrial cameras, median filter and an edge detection image processing algorithm are adopted to seek pixel positions at two side edges of a steel plate in the obtained steel plate images, a polynomial fitting method is adopted to accurately calculate sub pixel coordinates around the two side edges of the steel plate, and at last the lateral deviation distance of the steel plate is obtained; according to the lateral deviation distance of the steel plate, thickness compensation quantity of a rolling mill operating side and a rolling mill driving side is confirmed, wherein the thickness compensation quantity is needed when correction is conducted after camber occurs in the steel plate; according to the thickness compensation quantity of the rolling mill operating side and the rolling mill driving side, roll gap compensation regulating quantity is confirmed through a bounce equation of the rolling mill; the roll gap compensation regulating quantity is accumulated to original roll gap regulation setting, a roll gap is regulated by controlling a servo valve through a rolling mill hydraulic control system, and therefore the correction of the camber is achieved.