An upside-down type LED light source for supplemental lighting for plants includes a substrate, an LED chip, a first glue powder layer, and a second glue powder layer; the LED chip is mounted on one surface of the substrate; the LED chip being a blue LED chip; the first glue powder layer is disposed between the LED chip and the substrate, and the LED chip is covered by the second glue powder layer; the LED chip is fixed on the substrate through the first glue powder layer, wherein the first glue powder is a mixture of a glue and red phosphors; and the second glue powder layer covers the LED chip and completely wraps the LED chip; the second glue powder layer is one of a mixture of the glue and yellow phosphors, and a mixture of the glue and infrared phosphors.