Abstract: This article uses principal component analysis to reduce the meteorological dimension,extracts comprehensive evaluation indicators that are not related to each other,and uses the extracted main components as independent variables of the regression model to establish a multiple linear regression model.By verification,it is found that the goodness of fit of the principal component regression model is better than that of the direct regression model,which improves the prediction accuracy and the prediction results are more stable.Therefore,the principal component analysis method can effectively improve the prediction accuracy of photovoltaic power generation.