In order to reasonably reduce the backlight power consumption of the liquid crystal display, suppress the clipping noise caused by pixel compensation and reduce the color and brightness distortion of the display image, the dynamic dimming algorithm of the liquid crystal display based on image features is studied. Firstly, according to the characteristics of liquid crystal display, the process of regional dimming algorithm is introduced, and the cause of clipping noise is analyzed. Then, the dynamic dimming algorithm of liquid crystal display based on local brightness of image is proposed to obtain the initial backlight value based on the maximum value method. The initial backlight value is corrected according to the similarity between the brightness of the local area of the image and the brightness of the corresponding area of the initial backlight distribution image. Through the Blur Mask Approach, the mixed light diffusion process of the backlight is simulated, and combining pixel compensation, a dimming image is obtained. The experimental results show that the backlight power consumption is reduced by about 31.54% on average, the truncation noise is as low as 1.17% of the total pixel, and the L*a*b color space peak signal-to-noise ratio(LabPSNR) is 37.11 dB on average. The application of the algorithm can reasonably reduce the backlight power consumption of the display, so that the truncation noise of the image is significantly suppressed, the color and brightness distortion are obviously improved, and the applicability is good for various images.