Both the mathematical principle of the maximum probability (MP) method and the process of iterative equations are introduced. Then we use the real satellite data as an example to demonstrate the calculation of MP method and obtain the volume scattering ratio profiles and scattering coefficient profiles of polar mesospheric clouds (PMCs). We compare the inversion results of the MP method with those of the traditional onion peeling (OP) method, and find that the former hardly have any distortion, while the latter show serious distortion. The fundamental reason for this difference is that the OP method assumes that the volume scattering intensity has a uniform distribution in the same atmospheric layer, while the MP method assumes that the volume scattering intensity can exhibit a non-uniform distribution within a certain varied range of the layer. This assumption of MP method is more suitable for the natural characteristics of PMCs, because the spatial distribution of PMCs often changes greatly in a short time.