The prevent invention provides a plant growth system, a plant planting method and an illumination device. The plant growth system includes a plurality of lighting modules, which individually generates a plurality of light sources, respectively. Each light source is different from each other. The plurality of light sources provide corresponding light spectra that respectively matches a plurality of predetermined growth spectra of a plurality of plants. One of the plurality of light sources produced by one of the plurality of lighting modules radiates the corresponding plant, such that the light spectrum provided by the lighting source is applied to the corresponding plant.本發明公開一種植物培養系統、植物培養方法以及照明裝置。植物培養系統包括多個照明模組。多個照明模組分別相對應地產生多個不同的照明光源,且多個不同的照明光源分別相對應地提供多個不同的照明光譜,且多個不同的照明光譜分別相對應地配對於多種不同植物的多個不同的預定生長光譜。多個照明模組的其中之一所產生的照明光源投射在相對應的植物上,以使得照明光源所提供的照明光譜應用於相對應的植物。藉此,本發明可根據不同植物所需的不同生長光譜,以及同一植物在不同生長階段所需要的不同生長光譜而供應一對應於每一植物的每一生長階段所需的生長光譜的照明光源,以提高植物的生長效率。