The utility model discloses a photovoltaic power generation system of a 110 kilovolt transformer station micro-grid. The system includes a photovoltaic assembly, a direct current lightning protection combiner box being in circuit connection with an output terminal of the photovoltaic assembly, and an inverter being in circuit connection with an output terminal of the direct current lightning protection combiner box; and an output terminal of the inverter is accessed in a common connection point AC bus of the transformer station micro-grid. The photovoltaic power generation system disclosed by the utility model is suitable for a micro-grid system, to act as a distributed power source of the micro-grid system and provide clean environmentally friendly energy, so the electric power requirement of the micro-grid system can be met; and the inverter is connected with the common connection point AC bus, problems of large fluctuation and randomness in a conventional photovoltaic power generation system can be solved.