With the study on numerical simulation of indoor illuminance, we find CIE clear sky model and CIE overcast sky model can be used for relative precise estimation of indoor daylight distribution, meanwhile, the calculating time and PC memory space are saved. 2通过对建筑物室内照度数值模拟研究发现,采用CIE晴天天空模型和CIE阴天天空模型既能较准确地预测建筑物的室内天然光分布,又能有效地节省运算时间和计算机存储空间;