In order to improve the light efficiency of wide color gamut liquid crystal displays(LCD),this paper proposed a reflective color filter. First,the enhancement effect of the light efficiency of the reflective color filter was calculated. Then,a multi-layer stack structure ([ABCCBA](8)) of the color filter was designed based on low,medium,and high refractive index materials. Using white light emission diode backlight unit with yellow phosphor (YAG-LED) and quantum dot (QD) backlight unit, the light efficiency was increased from 17. 4% to 32. 9% and from 18. 5% to 58. 9%,respectively. At the same time,the color gamut of this structure also improved to 120. 7% NTSC and 131. 2% NTSC. Considering the role of the scattering film in the backlight module,the light efficiency of LCD with YAG-LED and QD backlight unit is still greater than 32% and 56% respectively when the incident light angle is within 20 degrees. The color gamut remains essentially unchanged. These results hold significant potential for applications in wide color gamut LCD.