According to the differences between the white LED spectrum and the visible light spectrum, the feasibility of using optical coating to improve the spectrum is discussed. Meanwhile, a novel method is proposed to eliminate blue band of the white LED spectrum. The transmittance of the required optical coating is calculated, and the feasibility of method is analyzed. According to the spectrum of the single LED is different at the different temperatures, the transmittance of the required optical coating is calculated based on the spectrum of the single LED at the temperature 4.9°, 24°, 49°, and the feasibility of using optical coating to improve the temperature stability of the single LED spectrum is analyzed. The results show that the method of using optical film coated on the LED chip does not improve the structure of the white LED to make it similar with the visible light spectrum. The blue band of the white LED spectrum can be eliminated and improve the comfort of the spectrum using the designed optical thin film. The center wavelength and the relative luminous of the analyzed single LED can be stabilized at the 700 nm and 0.2 at the temperature 4.9°, 24°, 49° using the designed optical film. The similarity of the spectrum at the different temperature is improved greatly. The results contribute to the further application of LEDs.