The present invention discloses an electric energy control circuit for a solar power illumination system. The solar power illumination system has at least one solar panel coupled to a charging controller, and the solar panel charges at least one battery via the charging controller. An electric energy control circuit according to the present invention controls a driving unit to acquire electric energy from the battery and turn on at least one lamp set. The electric energy control circuit comprises: a power detection loop and an output control loop. The power detection loop is coupled to the solar panel and the battery and detects the power generation of the solar panel and the remaining capacity of the battery. The output control loop is coupled to the power detection loop and determines the power output to the lamp set according to the power generation and the remaining capacity. Thereby, the present invention can modulate the power for the solar power illumination system according to the weather, prolong the power supply time of the battery, and reduce the bad weather-induced attrition of the solar power illumination system.