Abstract: The integration of membrane distillation and heat transfer network is an effective way to reduce energy consumption and also a typical water energy relation system. A mathematical model is established for the integration of membrane distillation system and heat exchange network. The integrated system is compared with the separate system to test the proposed integration system. The sensitivity analysis of membrane distillation feed water temperature and membrane specifications on the system economic performance are conducted. The results show that the integrated system is better than that of the separate system in economic performance, and the higher the feed water temperature, the better the system economy. The most economical membrane is PTFE membrane, followed by MD020CP2N membrane, GVHP membrane and PVDF membrane under the same inlet temperature and a certain scale of water treatment system.