One major method to decrease threshold current density of the semiconductor laser and enhance the deferential exterior of the quantum-efficiency is choosing desirable reflectance of light on both ends of light-emitting chip. This paper provides the contents of optimizing coating system based on optical thin film design theories. The design of optical thin film is prepared with desirable materials, assisted with electron-beam evaporation technology. The optical dielectric film was deposited on two end surfaces of light-emitting chip which has 100 μm stripe width and 1mm length in semiconductor laser. Through the process, it obtains the specific properties of optical spectrum as well as obtuse light emitting vertical cavity surface. It decreases material absorption and enhances laser damage thresholds through optimizing parameters of optical film deposition. After testing, the output power of the high-luminous semiconductor laser′s luminous CMOS chip is improved to 3.7 W. The power has been raised by 2.8 to 3.1 times than the uncoated apparatus.