The lighting technique of LED has experienced substantial progress. However, a single LED cannot meet the demand for the normal lighting. LED combination is usually adopted to achieve the desired lighting effects. The forms of LED combination are varied. A detailed optical analysis on four forms of LED planar array is taken by using Tracepro, which are 3×3 square array, 3-6 concentric array, Archimedean spiral array and 1-8 circular array. By the comparison, which find that 1-8 circular array is the best optimal design to reduce the waste of material and further improve the cost performance of LED lighting under the conditions of meeting the lighting requirements. A reference can be provided for the popularity of LED lighting.