An extensive summary in the application status of distributed Bragg reflectors in LED area and theoretically is analyzed its principle of suppressing the internal absorption in order to fabricate high performance especially for UV-LEDs grown on sapphire substrates with emission wavelengths below 362 nm.And a quantitative analysis on the relationship among the main factors which normally greatly influence the quality of distributed Bragg reflectors was given,such as:A.dependence of the absorption edge on the Al molar fraction,B.index of refraction at room temperature,C.influence of temperature on the optical properties,D.temperature dependence of the refractive index.