A plant growth apparatus includes: a main body, a plurality of light modules, and a heat sink. The main body includes a frame and a plurality of planar modules. The frame has a plurality of columns. The columns are connected to form the frame in defining a receiving space. The planar modules connect to the columns and encircle the receiving space. The light modules are disposed on the main body. The heat sink connects to the light modules. Wherein light beams are projected from the light modules to the receiving space, and heat form the light modules is conducted to the outside of the receiving space by the heat sink.一種植物生長裝置包括與一本體、多個發光模組與一散熱部。本體包括一框體與多個平面模組。框體具有多個支撐桿,這些支撐桿連接形成框體,並於框體內形成一容置空間。這些平面模組連接於這些支撐桿之間,且圍繞於容置空間外。發光模組設置於本體。散熱部連接於這些發光模組。其中這些發光模組輸出光源至容置空間,而散熱部將這些發光模組之發光熱源散逸於容置空間外。H1‧‧‧開口S‧‧‧容置空間1‧‧‧植物生長裝置10‧‧‧本體12‧‧‧發光模組14‧‧‧框體16‧‧‧平面模組18‧‧‧散熱部20‧‧‧光週期控制器100‧‧‧支撐桿120‧‧‧發光二極體122‧‧‧印刷電路板162‧‧‧入光面164‧‧‧出光面
