An improvement method for speckle phenomenon of a display image includes: a display device respectively displaying a first black-and-color grid image and a second black-and-color grid image; black and color grins of the first black-and-color grid image and black and color grins of the second black-and-color grid image are complementary, size of black and color grins of the first black-and-color grid image and the second black-and-color grid image is same as pixel size of the display panel; and acquiring a pixel gray scale of the first black-and-color grid image the display device displays; the display device displaying an image according to the acquired pixel gray scales and a driving frequency. The method calibrates the pixel gray scale of the display device by way of compensation and algorithm to achieve brightness uniformity of the display screen and reduce or eliminate the speckle phenomenon caused by the AG cover glass.