In　order　to　find　out　the　vortex　tube　configuration　with　the　best　cooling　temperature　difference,　nozzles　with　different　Mach　numbers　were　designed　and　manufactured,　the　experimental　system　was　set　up　and　the　performances　of　these　nozzles　were　measured.　The　result　shows　that　the　vortex　tube　has　better　energy　separation　effect　with　outlet　Mach　number　between　0.5　and　0.8.　But　when　the　Mach　number　is　up　to　0.9,　the　effect　would　be　worse.　The　refrigeration　performance　of　the　vortex　tube　with　the　outlet　Mach　number　of　0.8　is　best　from　0.4　to　0.6　MPa　in　inlet　pressure,　but　the　performance　difference　varied　little　with　input　pressure　over　0.6　MPa.