A lighting device with cooling function and a system applying the lighting device includes a first casing, a second casing, a fluorescent tube, and a cooling fan. Therein, the second casing is made of a material pervious to light, and combined to the first casing, thereby forming a space between the first and second casing. The fluorescent tube is disposed in the space. The cooling fan is disposed in the space, thereby producing a heat exchange between the space and outer environment and thus cooling the temperature within the space. Therefore, the lighting device becomes a lighting module, which can be applied in the plant factory and thereby minimizes the effect to crops caused by high temperature.本發明係提供一種具有降溫功能之燈具及使用該燈具之照明系統,其中具有降溫功能之燈具,包括有:一第一殼體;一第二殼體,係為一可透光之材質製成,其結合於第一殼體,以使第一殼體與第二殼體之間形成一空間;一燈管,係設置於空間內;以及一降溫風扇,係設置於空間內,用以使空間與外界進行熱交換,進而降低空間內之溫度,如此燈具可模組化並構成一照明系統,且運用於植物工廠內,以降低照明所產生之高溫對於農作物之影響。10‧‧‧第一殼體12‧‧‧內表面121‧‧‧反光材質14‧‧‧第一支撐件141‧‧‧抵接面20‧‧‧第二殼體22‧‧‧空間23‧‧‧第二支撐件231‧‧‧抵接面24‧‧‧第一結合部25‧‧‧第二結合部30‧‧‧燈管31‧‧‧第一電連接部32‧‧‧第二電連接部40‧‧‧降溫風扇50‧‧‧濾網
