Considering the direct current drive electrical power from 0.5 W to 6.5 W on a different heatsink and the thermal resistance from 1℃/W to 30.5℃/W as optimization variables,a series of calculations are performed in order to obtain the target variables which are the objective function of luminous flux from 40 lm to 460 lm and correlated color temperature from 7 100 K to 8 600 K. The spectral power distribution of white light-emitting diodes was optimized using a combination of the photo-electro-thermal theory and multi- spectral power distribution modeling. When the objective function is close to 5%,the optimized results of SPD is obtained. The work provides a reference for practicing LED system designers to optimization an LED system.