In this paper, we simulate and analyze the scattering effect in phosphor based on Mie scattering theory. And then we build a precise optical model in silicon phosphor by using Monte Carlo ray tracing. The optical properties of simulation of our phosphor model have been verified successfully in the rigorous process of experiment. According to this model, we can simulate precisely the optical properties corresponding to the various combinations of parameters like diameter size of phosphor particle, concentration of phosphor, and package structure. Additionally, we design a special package type with high efficiency and little deviation of space color temperature for the white light LED.