Aiming at the PV power output prediction without enough accuracy, a PV output prediction model that combines Singular Spectrum Analysis (SSA), K-means clustering, Time delay characteristics (TD), and BP neural networks is proposed. Using the similar day theory to select a variety of weather types as training samples, through the decomposition and reconstruction of the singular spectrum analysis, the trend and quasi-period components contained in the time series are extracted, using K-means clustering method to cluster the reconstructed weather samples into K types. Using temperature, wind speed, weather type, and historical output as sample attribute, each weather type is processed by a delayer to form a sample set with delay characteristics. This sample set is used as the input of BP neural network to construct a TD-BP neural network PV power forecast model based on SSA and K-means. The results show that the model has more accurate forecast for PV output power and has certain feasibility and practicality. © 2021, Solar Energy Periodical Office Co., Ltd. All right reserved.