An　experimental　system　was　set　up　for　wet　air　supersonic　condensation　research.　The　stability　measurement　tests　were　taken.　The　results　showed　that　the　experimental　system　at　least　needed　10　h　to　achieve　stabilization.　The　supersonic　condensation　process　of　wet　air　in　Laval　nozzle　was　tested.　The　results　showed　that　the　droplet　diameter　is　nearly　0.85　μm　along　the　axial　without　obvious　fluctuation,　and　the　droplet　number　is　nearly　3.0　×　1012#　·　kg-1,　and　the　liquid　fraction　is　neatly　8.0　×　10-4　when　the　inlet　pressure　of　the　nozzle　was　0.46　MPa.　Mathematical　models　of　wet　air　were　set　up　to　simulate　the　process　of　homogeneous　and　heterogeneous　condensation　in　Laval　nozzle.　The　results　showed　that　the　experimental　results　were　in　agreement　with　heterogeneous　condensation　simulation　results　which　validated　the　heterogeneous　model.　©　All　Rights　Reserved.