The present disclosure discloses a passive optical network (PON) user terminal comprising a passive optical network interface unit (PONIU) having access to a PON system, a service data distribution unit (SDDU) connected to the PONIU for distributing service data, a plurality of service processing units (SPUs) for receiving and accordingly processing the service data distributed by the SDDU, a power source for providing power to the above units, and a power supply control unit (PSCU) for controlling the activating/deactivating of the energy-saving power supply to the SPUs, the SDDU, and the PONIU. The present disclosure further provides a method for controlling the PON power supply and for reporting the power supply state. The present disclosure allows control of the energy usage of the PON user terminal to save power when a service in the PON user terminal is not used or when the user terminal uses a backup power source to supply power.