Abstract: Electricity is directly used in traditional membrane distillation to provide energy,and the energy consumption is high. In this paper,a vacuum membrane distillation system based on solar thermal and photovoltaic technology was designed and built. The changes of heating stability,membrane flux and cumulative water production under different weather and solar irradiance were investigated,and the effects of different operating conditions such as feed temperature,salt concentration,flow rate and vacuum degree on the water production performance of membrane distillation system were revealed. The results show that the heating stability of the system is good both in sunny and cloudy days. The temperature of the feed liquid can reach above 60 ℃ for 9.5 h on a sunny day. When the area of the CPV/T device is 3 m~2,the area of the vacuum tube collector is 2.4 m~2,the area of the membrane is 0.1146 m~2,and the total membrane flux of the whole system can reach 10.1 kg/（m~2·h）,and the accumulated water production can reach 10.3 kg. The vacuum degree and feed temperature have a of great influence on the water production performance while the effect of feed flow rate and salt concentration is relatively small.