In　order　to　improve　the　flow　stability　when　wafer　scans　at　high　speed,　immersion　lithography　with　small　flow-thickness　is　proposed　for　the　high　resolution　lithography.　By　using　the　numerical　methods,　the　immersion　flow　is　investigated　to　analyze　the　behaviors　of　liquid　flow.　Based　on　the　flow　characteristics　of　typical　structures　with　different　liquid　thickness　and　scanning　speed,　the　liquid　mean-velocity　on　account　of　thousand　sample　points　in　the　exposure　area　are　studied,　and　the　appropriate　parameters　and　method　of　effective　renovation　with　small　thickness　are　also　given.