The invention relates to an ecological residence electrical energy system and a power supply control method. The system comprises a power supply system which consists of a plurality of power supply sub-systems, an electrical energy output interface which is connected with the power supply system and external electrical devices, a controller which is connected with the power supply system, wherein the controller is used for detecting the electrical energy output condition of the power supply sub-systems in real time, the condition and the target electricity consumption of the acquired electrical device in advance are compared, a total power supply amount is selected to ensure that the power supply sub-systems of the target electricity consumption are combined to form a target power supply sub-system assembly, and the connection of other power supply sub-systems and the electrical energy output interface is cut off. In the prior art, a photovoltaic system is adopted, the power supply stability is affected, and the problem of energy waste due to the fact that a plurality of power supply systems coexist is solved.