The present disclosure provides a method for adjusting display image contrast, which includes the following operations: in response to receiving an image signal, acquiring an image to be displayed and metadata according to the image signal, and calculating a signal amplitude corresponding to each pixel of the image to be displayed; generating a histogram showing a distribution of the signal amplitude according to each of the signal amplitudes, and acquiring display information and a backlight adjustment parameter of the image to be displayed according to the histogram; generating a signal adjustment function according to the display information, the backlight adjustment parameter, and the metadata, and adjusting the signal amplitude of each of the pixels according to the signal adjustment function to adjust a contrast of the image to be displayed. The present disclosure further provides a display and a readable storage medium. The cost of improving the display image contrast of the present application is low.