Due to the instability and unsatisfactory prediction of the generating capacity, the photovoltaic power is hard to directly connect to the electric grid. Dust deposition is one of the key impact facts for the photovoltaic power, but its effect cannot be predicted through a reasonable physical model, and it became a hot research topic. This paper proposed a comprehensive physical model to predict the impact of the deposition on the light transmittance of solar panel. This model involves some physical parameters of the deposition, which made it applicable widely. In addition, the results indicate the influence of deposition prominently increased with the raise of the concentration and the size of the particles, but decreased with the changes of particle diaphaneity. (C) 2018 Elsevier Ltd. All rights reserved.