After decades of technological improvement, LED's luminous efficiency has been greatly improved. The lighting effect of incandescent lamps and halogen tungsten lamps is 12-24 lumens/watt, fluorescent lamps 50-70 lumens/watt, and sodium lamps 90-140 lumens/watt. Most of the power consumption becomes heat loss. The improved LED light efficiency will reach 50-200 lumens/watt, and its light has good monochromaticity, narrow spectrum, and can directly emit colored visible light without filtering. At present, countries all over the world are stepping up research on improving the luminous efficiency of LEDs, and their luminous efficiency will be greatly improved in the near future.