A light control device and method for stimulating plant growth is disclosed. The light control device includes a light source capable of emitting light required for plant growth. The light control device further comprises a plurality of light conversion films rotatably mounted upon a film switching unit arranged around the light source, the film switching unit driven by a motor arranged therewithin. The plurality of light conversion films may further provide a plurality of light spectra required during a plurality of plant growth stages. The light control device determines plant growth stage based on the size and the height of the plants. The motor rotates the film switching unit, based on the plant growth stage of the plants, in such a manner that a light conversion film, associated with the plant growth stage of the plants, is positioned in front of the light source. Such positioning stimulates the plant growth.