Water　serves　as　an　indispensable　part　of　human　life　and　production.　On　account　of　the　overexploitation　of　traditional　water　sources,　the　demand　for　wastewater　recycling　is　expanding　rapidly.　As　a　promising　water　treatment　process,　membrane　distillation　(MD)　has　been　utilized　in　various　wastewater　treatments,　such　as　desalination　brine,　textile　wastewater,　radioactive　wastewater,　and　oily　wastewater.　This　review　summarized　the　investigation　work　applying　MD　in　wastewater　treatment,　and　the　performance　was　comprehensively　introduced.　Moreover,　the　obstructions　of　industrialization,　such　as　membrane　fouling,　membrane　wetting,　and　high　energy　consumption,　were　discussed　with　the　practical　investigation.　To　cope　with　these　problems,　various　strategies　have　been　adopted　to　enhance　MD　performance,　including　coupling　membrane　processes　and　developing　membranes　with　specific　surface　characteristics.　In　addition,　the　significance　of　nutrient　recovery　and　waste　heat　utilization　was　indicated.　©　2021　by　the　authors.　Licensee　MDPI,　Basel,　Switzerland.