The present paper mainly studies the influence of the junction temperature on the white LED spectral characteristics of the mixture of the DCJTB and YAG∶Ce3+ phosphor. With layered coating of YAG phosphor and organic materials DCJTB on the LED chip with the method of hierarchical point powder, the color rendering index of the device will reach up to 90. The junction temperature can be measured conveniently and accurately with the integrated LED cooling pad which was developed by the laboratory. Experiments show that: the rise of the junction temperature can make the radiation amplitude of the blue chip decline continuously. The yellow radiation amplitude of YAG phosphor which is excited by radiation first increases and then decreases, the red spectrum is blue-shifted, the color rendering index of the device decreased linearly, while the color temperature first increases and then decreases.