A power supply having a power protection circuit has a rectification circuit and a converter. An input terminal of the rectification circuit is connected with the AC mains. A first voltage dependent resistor is connected with the AC mains. The converter has a transformer. A primary side of the transformer is connected with an output terminal of the rectification circuit, and the secondary side is connected to a power output terminal and a ground terminal. A Y capacitor is connected between the primary side of the transformer and the ground terminal. A surge protection module is connected between the first voltage dependent resistor and the Y capacitor. When a surge occurs between the primary and secondary sides of the transformer, a surge current is shunted by the surge protection module to the ground terminal through the Y capacitor without damaging internal components or circuits inside the power supply.