Membrane distillation is a distillation technology that has emerged in the last 50 years.Compared with the traditional thermal distillation, membrane distillation has the advantages of compact structure, simple device and easy operation, so many membrane distillation technologies have been developed up to now.Recently, a novel air gap diffusion distillation (AGDD) technique has been proposed.This paper mainly introduces the research progress of air gap membrane distillation, solarenergy distillation and humidification and dehumidification technology in recent years.