A power monitoring circuit having an automatic feedback function and an overload protection function is described. The power monitoring circuit has a current detection module, a voltage detection module, a multiplication module, and an overload protection module. The current detection module is used to obtain the current value of a power supply path. The voltage detection module is used to obtain the voltage value of the power supply path. The multiplication module generates the power value of the power supply path with reference to the current value and the voltage value. The overload protection module determines, with reference to the power value, whether to switch off the input of the power supply path, so that the overload protection module protects the system load connected to the power supply path. The current detection module, the voltage detection module, and the multiplication module are integrated into a chip.