The invention discloses a photovoltaic single-phase access capacity configuration method favorable for reducing three-phase imbalance of a transformer area. The method comprises steps of acquiring three-phase load, illumination intensity and air temperature data of the transformer area within one year, fitting the three-phase load, the illumination intensity and an air temperature daily change characteristic curve, based on the three-phase load daily change characteristic curve, obtaining an optimal daily change characteristic curve of each phase of photovoltaic injection power capable of reducing three-phase load imbalance of the transformer area to the greatest extent, based on the illumination intensity and the air temperature daily change characteristic curve, obtaining a power outputcurve matched with the optimal daily change characteristic curve of the photovoltaic injection power of each phase to the maximum extent, and calculating the photovoltaic access capacity of each phase. The method is advantaged in that the three-phase load characteristic data of the transformer area are extracted, and the photovoltaic capacity of single-phase access is determined by combining the three-phase imbalance condition, so the three-phase imbalance degree of the transformer area is reduced.