The invention provides an off-grid and grid-connected operation light and storage joint power supply system which comprises a DC/AC converter for connecting a direct current bus and an alternating current bus. The alternating current bus is connected with a power grid. The alternating current bus and the direct current bus are connected with an alternating current load and a direct current load respectively. The direct current bus is connected with a photovoltaic array and a battery system through a photovoltaic DC/DC converter and an energy storage DC/DC converter respectively. According to the off-grid and grid-connected operation light and storage joint power supply system, control strategies of the off-grid and grid-connected operation light and storage joint power supply system are provided and include the off-grid state operation control strategy and the grid-connected state operation control strategy. By means of the system and a method, the defects that an existing photovoltaic power supply system is instable in power supply quality, poor in schedulability, single in operation mode, low in energy conversion efficiency and the like are overcome.