Abstract: The present disclosure discloses a probability estimation method for photovoltaic power based on an optimized copula function and a photovoltaic power system. According to the method, weather types are classified by a clustering method to obtain a plurality of weather types, clustering is carried out based on historical meteorological data, and a copula function model is constructed based on clustering results. Historical operation data and weather classification results are considered at the same time to make the obtained hybrid Copula function model have higher prediction accuracy.