The invention mainly discloses a lighting system for plant growth. The lighting system for plant growth has at least one lamp for plant lighting, and a cabinet arranged above the lamp. The lamp is hanged by a lifting mechanism in the cabinet for lifting and lowering operations. A mechanism for lifting and lowering the lamp according to plant growth height within a height limited by the system is planned； and the mechanism is configured to have at least two sets of sensing device sets having transmitting and receiving ends and arranged with an independent timing devices to control on/off thereof, so as to avoid long-term power consumption and abnormal interference. Through using the sensing device sets to ensure that the lamp can be lifted and lowered to keep a certain distance with the crown and the sensing device sets are installed parallelly, vertically or interlacedly. A lighting system for plant growth can lift and lower the lamp according to the changes of the height of the plant at different growth stages, so as to provide the plant the required lighting conditions at different growth stages, and provide better lighting effect under different output powers, thereby achieving the purpose of reducing energy costs.本發明主要揭露一種用於植物生長照明系統。所述一種用於植物生長照明系統，係具有至少一供植物照明用燈具，於燈具上方處設有一機箱，藉由機箱內升降機構吊掛燈具進行升降動作，在系統限定之高度內規劃有依照植物生長高度升降燈具之機構；且機構係依至少兩組具有發射端與接收端感測裝置組其感測裝置組及設有獨立定時裝置，控制其啟閉，避免長期用電消耗與非正常性干擾。藉由感測裝置組確認燈具與株冠保持一定距離進行升降，其感測裝置組互為平行、垂直或交叉安裝。一種用於植物生長照明系統俾隨著植物在不同生長階段所產生的高度變化，將燈具予以升降，給予植物在不同生長階段所需光照條件，以及在不同輸出功率下，對植物產生較佳的光照效果，達到相對降低能源成本之目的。
