太阳光度计是地基探测整层大气光学参数的重要仪器，而在一些研究与工程应用中更需要了解低层大气光学参数。基于均匀平行球面大气分层的假定，提出了利用太阳光度计测量的数据确定分层大气平均消光系数的算法。应用该算法处理POM-02太阳光度计的实际测量数据，研究表明这种分层算法得到的大气总光学厚度与整层算法得到的大气总光学厚度的相对误差小于3%。利用该分层算法求得的低层大气平均消光系数与激光雷达测量的消光系数进行比较，两者具有较好的一致性。因此，这种利用太阳光度计测量数据确定分层大气平均消光系数的算法是可行的，该算法拓展了太阳光度计的应用。

Sun-photometer is one of the main instruments for ground-based detecting atmospheric optical parameter of whole atmospheric layer. The atmospheric optical parameters of lower atmosphere are more desiderated in some researches and projects. Based on the assumption of uniform parallel sphere of stratified atmosphere, a new algorithm for average extinction coefficient of stratified atmosphere measured by sun-photometer is put forward. When dealing with the data measured by sun-photometer POM-02, the relative error of atmospheric optical depth gained by stratified atmospheric algorithm and whole atmospheric layer algorithm is less than 3%. The atmospheric average extinction coefficient of lower atmosphere got by stratified atmospheric algorithm is compared with the atmospheric average extinction coefficient by lidar. The results show that they have a good consistency. Therefore, the stratified atmospheric algorithm is feasible, and it extends the sun-photometer′s application.