The invention provides a regional power prediction method for a photovoltaic power station group. The method comprises the following steps of: computing power prediction accuracy indexes of regional photovoltaic power stations and coefficients of correlation between the actual output power of each photovoltaic power station in an area and the actual total output power of the area; selecting a representative photovoltaic power station, and computing weight coefficients of the representative photovoltaic power station; and computing a generation power prediction value of a regional photovoltaic power station group. A power network dispatching department can realize regional prediction of photovoltaic generated power on the basis that parts of the photovoltaic power stations accomplish photovoltaic generated power prediction functions, so a generation plan of the following day is made according to a regional prediction result, a power network dispatching mode is optimized in a regional range, the quality of electric energy is ensured, the spare capacity of a system is reduced, the operating cost of a power system is reduced, and smooth implementation of a national new energy strategy is facilitated.