Because the aerosol type is very important in the inversion of optical thickness, it can greatly improve the inversion precision by using the most accurate aerosol type of the inversion area. Combined with the moderate resolution imaging spectroradiometer (MODIS) data, a mathematic model for solving the aerosol concentration ratio in Hangzhou area is proposed. By using the aerosol types of this mathematical model, the aerosol optical thickness can be obtained based on the 6S atmospheric model combined with the improved dense dark vegetation. The aerosol observation results are compared with aerosol values detected by AERONET sun photometer, which show that the inversion error absolute value is within 20% . The Hangzhou area atmospheric aerosol optical standard type 6S atmospheric model is given and the thicknesses of the inversion are compared with the inversion values using custom aerosol. The results show that the absolute value of retrieval relative errors of optical thicknesses by using aerosol types of custom value is 3% lower than that by using standard aerosol type value.