Abstract: Usually，ground take-off of solar unmanned aerial vehicle（UAV）will consume plenty of energy，so it has to carry batteries of higher mass，which greatly reduces the UAV′ s endurance capability. Based on this ，the author designed a new aerial take-off system of UAV ，the system consisted of ground console，lift-off power module，sensor module，spatial positioning and position holding module，take-off ejection system and aerial taxiing assistant system. The physical model was built through theoretical deduction，the energy consumptions of aerial take-off and ground take-off were compared by simulation calculation，thus the superior scheme of UAV aerial take-off was obtained.

Key words: solar unmanned aerial vehicle, aerial take-off runway, aerostat, energy consumption