A protection circuit includes a protection module and a fan electrically connected to the protection module. The protection module includes a control chip, an inverter, and an electronic switch. An input terminal of the inverter is electrically connected to a voltage output terminal and the fan, and further electrically connected to a clear pin of the control chip. An output terminal of the inverter is electrically connected to a preparation pin of the control chip. A first terminal of the electronic switch is electrically connected to an output pin of the control chip. The first and second terminals of the electronic switch are electrically connected to a power source terminal. A third terminal of the electronic switch is electrically connected to the voltage output terminal. When the fan short-circuits, the power source terminal stops supplying power to the fan through the voltage output terminal.