Aiming at the problem that the current microLCD brightness can not meet the brightness requirements of airborne helmetmounted displgy, a novel backlighting structure form and design principle were proposed, and the optical system was designed using the CODEV software. The light distribution effect of the backlight module was simulated using the LIGHTOOLS software. The results show that, when taking 85 lm green LUXEON Rebel LEDS as the light source, its output brightness is close to 160 000 cd/m2, uniformity is greater than 85%, and power consumption is only 1.25 W, which meets the requirements of the airborne helmetmounted display.