The present disclosure provides a compensation method and compensation device for a display screen, and a display device. The compensation method includes: adjusting a charging time for a plurality of areas of the display screen so that the charging time for each area to be charged is positively related to a distance from the each area to a data voltage input terminal of the display screen; comparing a first grayscale value before compensation of a sub-pixel in an i-th row and j-th column with a second grayscale value input to a sub-pixel in an (i-1)-th row and j-th column, where i and j are both positive integers, and i>1; searching a grayscale compensation parameter corresponding to the first grayscale value and the second grayscale value from a grayscale compensation parameter table in a case where the first grayscale value is not equal to the second grayscale value; compensating the first grayscale value by the grayscale compensation parameter to obtain a third grayscale value; and inputting the third grayscale value to the sub-pixel in the i-th row and j-th column for display. In the present disclosure, it is possible to allow that the display screen when displaying an image may reach a desired target grayscale value, thereby improving the display effect.