An actual packaging structural of high power three-chip white LED lamp is designed. The highest temperature of LED chip is 111.2°C, and the temperature range of heat sink is 72.6°C～73.8°C by finite element method (FEM). The respective temperature of lead frame and heat sink are 76.0°C and 71.0°C, which are measured by the thermocouples experiment. Based on the consistency between simulation results and experiment data, considering the steady temperature distribution of the lamp and heat transfer theory, several optimization methods are proposed. The effects of copper pad dimension, solder paste area and natural convection coefficient on the temperature field distribution are calculated.