A power apparatus, a current detecting circuit and a current detecting method are provided. The power apparatus includes a power conversion circuit and the current detecting circuit. The power conversion circuit generates an output current. The current detecting circuit includes first and second current sensing resistors and a control circuit. The first current sensing resistor and the second current sensing resistor sense the output current to generate first and second sensing voltage, respectively. The control circuit receives the first sensing voltage and the second sensing voltage, and converts the first sensing voltage and the second sensing voltage respectively into a first current sensing value and a second current sensing value. The control circuit triggers a protection mechanism when the first current sensing value is greater than a first overcurrent protection value. In the case where the first current sensing value is not greater than the first overcurrent protection value, the control circuit triggers the protection mechanism if the second current sensing value is greater than a second overcurrent protection value. The first overcurrent protection value is greater than the second overcurrent protection value.