The invention provides a photovoltaic generating optimization scheduling method based on prediction of uncertainty and clearance output. The method comprises the following steps: (1), according to a photovoltaic generating clearance model, obtaining a clearance output P clearance; (2), calculating a photovoltaic generating admission capability; (3), determining whether photovoltaic generating is in a limiting period; (4), performing optimization distribution on the power of a photovoltaic power station in a limiting period; and (5), outputting a generating scheduling plan of the photovoltaic power station. The photovoltaic generating optimization scheduling method provided by the invention is used for guiding scheduling of the photovoltaic generating, improves the system safe stable operation level and the system photovoltaic generating adsorptive capacity, reduces limited electric power of the photovoltaic generating, and improves the utilization rate of the photovoltaic generating.