The invention relates to a photovoltaic microgrid anti-reverse connection protection system of a large-scale grid connected photovoltaic power generation station, in particular, a photovoltaic microgrid anti-reverse connection circuit. The photovoltaic microgrid anti-reverse connection circuit comprises an optocoupler, a first diode, a relay, a control loop, a driving power source, a circuit breaker installed between a photovoltaic bus-bar and solar power source input, and a shunt release which controls the tripping of the circuit breaker; the first diode is in homodromous series connection with a light emitting diode at an optocoupler input side; and the cathode of the first diode is connected with solar power source positive-pole input. According to the photovoltaic microgrid anti-reverse connection circuit provided by the technical schemes of the invention, the shunt release is driven to be electrified and act through the optocoupler, the control loop and the relay, so that the circuit breaker trips, and a circuit can be switched off instantaneously, and therefore, later-stage electrical equipment can be protected; the control loop only samples the current direction signals of the solar power source input, and therefore, power consumption is not generated, action is flexible, and cost is low; and the shunt release controls the tripping of the circuit breaker, and therefore, the probability of failure or damage is very small, and high reliability can be realized.