The invention discloses a power generation capacity prediction method for large-scale wind power integration and a corresponding information management system. The method includes the steps that according to a wind speed history database and a physical module simulation database of a wind power farm, an original data set is obtained, off-line wavelet de-noising is performed, normalization processing is performed according to the months, and therefore multiple training data groups are obtained to train different neural network models; according to real-time wind speed data, the weight systems of the neural network models are calculated; the neural network models are combined according to the weight systems to obtain a mixed neural network prediction model; according to a preset prediction time interval, the input variable and the output variable of the mixed neural network prediction model are determined; according to the mixed neural network prediction model, wind speed prediction and reverse normalization treatment are performed, so that a corresponding wind speed prediction value is obtained, and the output capacity of the wind power farm is predicated. By the utilization of the power generation capacity prediction method and the corresponding information management system, a power grid dispatching and operating department can improve the power generation capacity management of a grid connection power plant, reasonably arrange the operation mode, increase the renewable energy source output and reduce pollutant discharge.