The influence of the factors such as the LED chip size, the emission half Angle and the distance from the luminous surface to the LCD panel layer in Mini LED backlight modules, on the illumination uniformity of the LCD crystal panel was studied and analyzed with Taguchi experimental method and Tracepro software. The results show that the distance from the luminous surface to the liquid crystal layer has the greatest influence on the illuminance uniformity, and the weight of the influencing factors is 82.88%, and that of the luminous half angle and the chip size is both 14.33%. According to the research results, the optimal illumination uniformity is obtained by fixing the luminescence half angle and the chip size and adjusting the distance between the luminous surface and the LCD panel layer.