The invention discloses an island microgrid operation method based on fuzzy PI control. The method comprises the steps of establishing an island microgrid operation model, wherein an island grid comprises master distributed generation and slave distributed generation; improving a droop controller in a v/f droop control system based on fuzzy PI; controlling operation of the master distributed generation through the droop controller, thereby obtaining voltage amplitude and frequency output by the master distributed generation; and converting the voltage amplitude and frequency into modulation signals and controlling the output power of an inverter of the master distributed generation according to the modulation signals. The fuzzy PI control is added to the droop controller in the v/f droop control system; on the basis of fuzzy reasoning, the droop controller can effectively control the voltage amplitude and frequency output by the master distributed generation; the output voltage amplitude and frequency are converted into the modulation signals; the output power of the master distributed generation can be effectively controlled according to the modulation signals; and the fluctuation of the voltage amplitude and frequency in the operation of the island microgrid can be further inhibited.