In　order　to　investigate　the　condensation　effect　on　Reynold　number　test　for　the　cryogenic　wind　tunnel,　a　two-phase　condensing　flow　model　was　established　based　on　the　Fluent　software.　The　classic　nucleation　theory　considering　the　non-isothermal　effect　and　Gyarmathy　droplet　growth　theory　were　employed　for　the　prediction　of　spontaneous　condensation.　Under　varying　inflow　pressures　and　testing　Reynold　numbers,　the　numerical　simulations　of　nitrogen　flowing　around　the　NACA　0012　airfoil　were　carried　out.　The　simulation　results　showed　that　the　decrease　of　incoming　flow　temperature　resulted　in　rapid　expansion　and　the　gas　supercooled　state　at　region　near　the　airfoil　surface.　With　further　reduction　of　the　incoming　flow　temperature,　significant　change　of　local　flow　fields　affected　by　condensation　was　observed　at　a　macroscopic　level.　The　release　of　latent　heat　heated　up　the　nitrogen　flow　and　thus　resulted　in　a　deceleration　of　Mach　number　and　a　deviation　of　pressure　coefficient　in　comparison　with　the　case　without　condensation.　Without　destroying　the　airfoil　aerodynamic　performance　test,　it　was　feasible　to　make　full　use　of　gas　supercooling　for　reducing　the　incoming　flow　pressure,　which　also　meant　few　cost　of　driving　power　and　liquid　nitrogen　injection.　Alternatively,　keeping　the　incoming　flow　pressure　constant　increased　the　testing　Reynold　number　of　the　cryogenic　wind　tunnel.　©　2020,　Editorial　Department　of　Journal　of　Aerospace　Power.　All　right　reserved.