The invention provides an ecological residence electric energy system and a power supply control method. The ecological residence electric energy system comprises a power supply system composed of a plurality of power supply subsystems, an electric energy output interface connected with the power supply system and electric equipment, a target electricity consumption obtaining unit connected with an electric equipment of a user to obtain the target electricity consumption of the electric equipment and a controller connected with the power supply system and the target electricity consumption obtaining unit, wherein one of the power supply subsystems is a photovoltaic power generation system. The controller is used for keeping the photovoltaic power generation system and the electric energy output interface communicated and detecting electric energy output of every power supply subsystem. Compared with the target electricity consumption, when generating electricity of the photovoltaic power generation system can not meet requirements of the target electricity consumption, the controller is used for selecting other power supply subsystems to compensate power quantity and keeping the selected other power supply subsystems and the electric energy output interface communicated. The ecological residence electric energy system and the power supply control method solve the problem that in the existing family household and during a power using process, abnormal operation of the electric equipment resulted from low power of the photovoltaic power generation system is solved.