The invention provides an optimal energy-saving control method for a light storage integrated power generation system. The method comprises the following steps: (1) collecting operating data of the light storage integrated power generation system; (2) calculating the power of the light storage integrated power generation system; (3) judging a photovoltaic circuit port current IPV and a photovoltaic port current threshold value Ith, and automatically searching a port voltage by a photovoltaic circuit if IPV is smaller than Ith; and (4) if IPV is greater than or equal to Ith, carrying out corresponding control by the light storage integrated power generation system according to energy storage SOC and inflow and outflow power sizes. According to the optimal energy-saving control method, optimal control for a photovoltaic power generation circuit is realized through the detection for photovoltaic output current and open-circuit voltage size, so that the system loss is effectively reduced, and the distributed photovoltaic utilization rate is improved.