This application discloses a network device and a method for determining a power supply relationship, and relates to the field of electric power technologies. The network device includes a plurality of power supply units, a plurality of radio frequency units, and a control unit. Each of the plurality of radio frequency units is connected to at least one of the plurality of power supply units. The control unit is connected to both the plurality of power supply units and the plurality of radio frequency units. The control unit is configured to: control a load on a first carrier to change in a first manner, where the first carrier is a carrier of any of the plurality of radio frequency units; obtain power consumption of the plurality of power supply units when the load on the first carrier changes in the first manner; and determine, from the plurality of power supply units based on the power consumption of the plurality of power supply units, a first target power supply unit that supplies power to the radio frequency unit corresponding to the first carrier, where a manner in which power consumption of the first target power supply unit changes matches the first manner.