At the beginning of the 21st century, commercial display has gradually developed into an independent industry. In order to improve the visual effects presented by wide color gamut full-color Mini-LED commercial display, to solve the problems of the poor color reproduction effect, large color difference and high price of the current Mini-LED splicing screen, a color gamut mapping method applied to Mini-LED commercial display is proposed. This method is based on the display characteristic file of Mini-LED, and the color gamut is mapped by the method of look-up table and tetrahedral difference. Then, according to the difference between the reduction effect and expression ability of different color features between Mini-LED splicing screens, the lookup table is optimized, and the balance of the mapping accuracy, mapping time and resource consumption is improved. The experimental results show that the maximum brightness loss of Mini-LED display after color gamut mapping is about 35%, and the uniformity of pixel intensity decreased from 8.2% to 4.9%, the color difference is reduced from 2.2ΔE to 1.3ΔE, which proves that this method has a good correction effect for the full-color Mini-LED commercial display in pixel intensity uniformity, chromatic aberration and other aspects, meanwhile the effect under visual observation is also improved to a certain extent.