The invention discloses a detection and correction method for printing dot area increase values. A detection strip on which multiple sections of screening step wedges are arranged for each color is attached to each printing sheet; multiple of printing sheets of different time periods are extracted; each color block on the detection strips is detected in a scanning mode, so that the spectral reflectance of each color block is obtained; color difference values of L*a*b*values of green, pinkish red, yellow and black solid color blocks of different ink zones of different printing sheets and standard L*a*b* values are calculated; then simple arithmetic mean values of color differences are calculated; weighted average values of dot areas of screening color blocks of each step wedge of each ink zone of which the color differences are smaller than the average color difference values according to color differences; then the dot area increase values are calculated; and correction values which are needed by digital documents for dot area compensation are calculated according to the average values of dot areas. The dot area increase values obtained in the invention can represent a current dot representation state of a printer more reasonably; dot area correction is performed more correctly; and the detection method is simple for operation and high in efficiency.