How　the　five　factors　(casting　solution　temperature,　intrinsic　viscosity,　polysulfone　concentration,　casting　temperature　and　dodecylbenzene　sulfonic　acid　sodium　salt)　in　preparation　affect　the　performance　of　polysulfone　thermal　phase　inversion　membrane　was　discussed.　And　microporous　membrane　with　their　average　pore　diameters　being　respectively　0.84　μm,　0.34　μm,and　0.16　μm　were　obtained.　By　means　of　SEM,　the　membranes　were　found　to　have　symmetric　spherical　porous　structure,　proving　themselves　to　be　microporous　membranes　resulting　from　the　thermal　phase　inversion.