The invention discloses a voltage and electrical energy condition pre-estimating method for a large photovoltaic power station. The method comprises the steps: processing acquired data of environment around the photovoltaic power station by a bivariate interpolation method, so as to obtain an environmental model of each place inside the photovoltaic power station; establishing a photovoltaic display model; establishing an inverter model; establishing a power grid side model; integrating the established photovoltaic display model, the established inverter model and the established power grid side model so as to establish a voltage and electrical energy condition pre-estimating model of the photovoltaic power station, namely taking output data of the photovoltaic display model as input data of the inverter model and taking output data of the inverter model as input data of the power grid side model; detecting voltage and current of the voltage and electrical energy condition pre-estimating model of the photovoltaic power station, thereby calculating electrical energy output condition and voltage quality of the photovoltaic power station. The method has the advantages that solar energy resources are sufficiently utilized, the cost is reduced, and greater economic and social benefits are obtained.