Supersonic　dehydration　is　a　new　technology　based　on　the　theory　of　gas　dynamic　and　heat　and　mass　transfer.　In　a　supersonic　process,　supersonic　separator　is　a　key　device　without　moving　part　capable　of　removing　the　condensable　phase　from　the　multi-component　natural　gas.　The　cyclone　flow　generator　plays　a　great　role　in　deciding　the　dehydration　performance　of　a　supersonic　separator.　Furthermore,　the　position　of　the　cyclone　flow　generator　also　has　a　significant　influence　on　the　flow　behavior.　In　order　to　investigate　the　variation　of　the　temperature,　pressure　and　velocity　inside　the　supersonic　separator　with　different　swirler　position,　a　computational　fluid　dynamic　(CFD)　model　is　established　to　simulate　the　high　speed　flow.　With　the　help　of　the　software　(FLUET),　different　flow　parameters　are　obtained.　The　calculation　results　show　that　the　backplaced-I　device　will　get　larger　temperature　drop.