A method for reducing display brightness, the method comprising: acquiring a transformed gamma curve, wherein the transformed gamma curve is a gamma curve obtained by reducing a grayscale voltage in an initial gamma curve according to a preset ratio and the preset ratio is smaller than 1 and more than 0; querying a corresponding grayscale voltage in the transformed gamma curve according to a grayscale pixel value of a pixel to be displayed; and at a scanning moment corresponding to the pixel, outputting the grayscale voltage to a data line corresponding to the pixel in a liquid crystal display screen, wherein before the step of acquiring a transformed gamma curve, the method further comprises: calculating the transformed gamma curve according to the initial gamma curve and the preset ratio; and storing the transformed gamma curve, wherein the step of calculating the transformed gamma curve according to the initial gamma curve and the preset ratio comprises: multiplying a maximum grayscale pixel value by the preset ratio to obtain a target grayscale pixel value N x; querying a grayscale voltage corresponding to the target grayscale pixel value N x in the initial gamma curve, and setting the grayscale voltage as a grayscale voltage V max corresponding to a maximum grayscale pixel value N max set as N x; querying a brightness value B max corresponding to the grayscale voltage V max in a brightness-voltage curve; measuring a brightness value B n corresponding to a grayscale pixel value N according to the following formula: N / N max gamma value = B n / B max; querying a grayscale voltage corresponding to the brightness value B n in the brightness-voltage curve as a grayscale voltage corresponding to the grayscale pixel value N; and obtaining the transformed gamma curve according to the grayscale voltage corresponding to the grayscale pixel value N and the grayscale voltage corresponding to the maximum grayscale pixel value N max; wherein the brightness-voltage curve comprises a corresponding relationship between brightness and a grayscale voltage, and a value range of N is [0, N max). acquiring a transformed gamma curve, wherein the transformed gamma curve is a gamma curve obtained by reducing a grayscale voltage in an initial gamma curve according to a preset ratio and the preset ratio is smaller than 1 and more than 0; querying a corresponding grayscale voltage in the transformed gamma curve according to a grayscale pixel value of a pixel to be displayed; and at a scanning moment corresponding to the pixel, outputting the grayscale voltage to a data line corresponding to the pixel in a liquid crystal display screen, wherein before the step of acquiring a transformed gamma curve, the method further comprises: calculating the transformed gamma curve according to the initial gamma curve and the preset ratio; and storing the transformed gamma curve, calculating the transformed gamma curve according to the initial gamma curve and the preset ratio; and storing the transformed gamma curve, wherein the step of calculating the transformed gamma curve according to the initial gamma curve and the preset ratio comprises: multiplying a maximum grayscale pixel value by the preset ratio to obtain a target grayscale pixel value N x; querying a grayscale voltage corresponding to the target grayscale pixel value N x in the initial gamma curve, and setting the grayscale voltage as a grayscale voltage V max corresponding to a maximum grayscale pixel value N max set as N x; querying a brightness value B max corresponding to the grayscale voltage V max in a brightness-voltage curve; measuring a brightness value B n corresponding to a grayscale pixel value N according to the following formula: N / N max gamma value = B n / B max; querying a grayscale voltage corresponding to the brightness value B n in the brightness-voltage curve as a grayscale voltage corresponding to the grayscale pixel value N; and obtaining the transformed gamma curve according to the grayscale voltage corresponding to the grayscale pixel value N and the grayscale voltage corresponding to the maximum grayscale pixel value N max; wherein the brightness-voltage curve comprises a corresponding relationship between brightness and a grayscale voltage, and a value range of N is [0, N max). multiplying a maximum grayscale pixel value by the preset ratio to obtain a target grayscale pixel value N x; querying a grayscale voltage corresponding to the target grayscale pixel value N x in the initial gamma curve, and setting the grayscale voltage as a grayscale voltage V max corresponding to a maximum grayscale pixel value N max set as N x; querying a brightness value B max corresponding to the grayscale voltage V max in a brightness-voltage curve; measuring a brightness value B n corresponding to a grayscale pixel value N according to the following formula: N / N max gamma value = B n / B max; querying a grayscale voltage corresponding to the brightness value B n in the brightness-voltage curve as a grayscale voltage corresponding to the grayscale pixel value N; and obtaining the transformed gamma curve according to the grayscale voltage corresponding to the grayscale pixel value N and the grayscale voltage corresponding to the maximum grayscale pixel value N max; wherein the brightness-voltage curve comprises a corresponding relationship between brightness and a grayscale voltage, and a value range of N is [0, N max).