Nowadays many enterprises lack of strict optical design and optimization to integrated light source, and the mould is opened just based on experience, which has low efficiency and high cost. Non-sequential Monte Carlo ray tracing method and optical simulation software Tracepro are used to do first optical design and optimization of integrated light source. Based on the structure of LED integrated package, a 7 W COB optical model is developed. Then, four variables of chip distances, bottom radius, depths of reflector cup and refractive indexes of silica gels are changed one by one to obtain the most excellent value of each parameter. The experimental results indicate some laws about the impact of chip distances, bottom radius, depths of reflector cup and refractive indexes of silica gels on luminous efficiency and light intensity distribution, which has guiding significance on the actual production.