Based　on　the　study　on　the　performance　of　gas　in　an　ultra-precision　air　bearing　stage,　the　effects　of　velocity　slip　and　viscosity　at　micro　scale　on　the　performance　of　air-bearing　stage　are　studied.　The　modified　film　flow　model　was　established　by　the　theory　of　gas　lubrication　and　the　research　of　slip　and　viscosity　in　micro　scale.　The　numerical　solution　of　the　Reynolds　equation　is　obtained　by　the　finite　difference　method.　The　influences　of　slip　and　viscosity　on　performance　of　air-bearing　stage　at　different　gas　supply　pressures　and　gas　film　clearances　are　analyzed　by　solving　Reynolds　equations.　The　result　shows　that　the　loading　capacity　is　smaller　and　the　stiffness　is　larger　when　considering　the　slip　and　viscosity,　while　the　influencing　trend　of　gas　supply　pressure　and　gas　film　clearance　on　the　air　bearing　stage　is　kept　the　same,　only　the　degrees　of　change　are　affected.　When　the　slip　and　viscosity　are　taken　into　account　at　the　same　time,　the　loading　capacity　is　decreased　by　21.95%,　and　the　maximum　stiffness　is　increased　by　15%.　The　optimum　performance　parameters　of　the　air　bearing　stage　are　less　than　the　ideal　optimum　performance　parameters　when　slip　and　viscosity　are　considered.　The　optimum　gas　film　clearance　is　changed　from　the　original　10　μm　to　6　μm.　Finally,　the　test　results　showed　that　when　the　slip　and　viscosity　are　considered　at　the　same　time,　the　stiffness　of　the　air　bearing　stage　is　close　to　the　actual　working　condition.　The　simulation　curve　of　the　loading　capacity　is　in　good　agreement　with　the　test　curve,　and　the　average　error　between　the　test　and　simulation　values　is　about　9.59%.　©　2017,　Editorial　Office　of　Journal　of　Xi＇an　Jiaotong　University.　All　right　reserved.