Abstract: The invention relates to the field of horticulture in a greenhouse and disclosures a system for supplementing light to plants, the system including a lighting grid and a power supply detachable from each other, wherein: the lighting grid includes a plurality of LED panels, wherein a plurality of LED lamps are arranged in each LED panel, and any adjacent LED panels are joined to each other by a joining member; and the power supply is electrically connected with the LED lamps in the respective LED panels through a cable.