Membrane　distillation　(MD)　demonstrates　excellent　desalination　application　potential　for　high　salt　concentration　wastewater.　However,　keeping　the　membrane　flux　and　rejection　high　during　long-term　operation　remains　one　of　the　critical　challenges.　In　this　work,　a　heat-stretching　treatment　method　was　proposed　to　improve　the　structure　of　polyvinylidene　fluoride　(PVDF)　hollow　fiber　membrane　and　enhance　its　stability　in　the　MD　process.　The　mem-brane＇s　pore　size　decreased　after　a　heat-stretching　treatment　in　water　at　120　C　for　1　h.　However,　the　liquid　entry　pressure　of　water　(LEPw)　value　and　membrane　strength　increased　significantly,　making　it　less　prone　to　pore　deformation　during　the　drying　or　MD　process　and　thus　improving　the　membrane　flux　and　stability　in　the　MD　process.　The　heat-stretching　treatment　made　the　PVDF　chain　arrangement　more　compact　and　oriented,　avoiding　shrinkage　in　the　length　direction.　Besides　stretching,　the　shrinkage　of　hollow　fiber　can　be　constricted　by　the　combined　effects　of　pore　filling　and　stretching　due　to　water　or　glycerol　filling　in　the　membrane　pores,　thus　eliminating　the　capillary　stress　caused　by　liquid　evaporation　during　the　air-drying.　Consequently,　the　heat　-stretching　treatment　broke　the　trade-off　between　high　permeate　flux　and　high　stability　in　the　MD　process.