Abstract: Fire image enhancement plays an important role in the system of fire detection based on images. A deficit of traditional fuzzy enhancement algorithms is the high computation cost. To solve this problem, a novel algorithm was proposed utilizing the 3-D look-up table (LUT) and a novel image fuzzy enhancement arithmetic operator. It firstly transforms the color space of fire images from red, green and blue to hue, intensity, saturaiton(HIS) and builds LUT for the variables I and S. Then enhances them through LUT and transforms the color space of fire images back to HIS space. Experimental results show that the new algorithm has significantly improved the running speed. It's helpful to the real-time detection of fire.