A photovoltaic power generation system includes a plurality of photovoltaic arrays, a plurality of shutdown units and an inverter. The shutdown unit is adjacent to the corresponding photovoltaic array, connected in parallel with the corresponding photovoltaic array, and electrically connected to the inverter via high voltage wires; the photovoltaic power generation system further includes a control unit configured to receive a detection signal indicating a state of the AC side of the inverter, monitor whether the AC side of the inverter is in a power-off state according to the detection signal, and generate a first power-off signal when the AC side of the inverter is in the power-off state; and the shutdown units are configured to receive the first power-off signal, and stop a power transmission from the photovoltaic arrays to the inverter according to the first power-off signal.