Nitrate　eutectic　salts　are　widely　applied　as　heat　transfer　and　thermal　energy　storage　medium　for　solar　thermal　power　plant,　and　the　corrosion　of　the　nitrate　eutectic　salt　to　the　system　device　has　become　challenge　to　the　safety　operation　under　high　temperature.　In　this　work,　the　dynamic　corrosion　behavior　of　316　and　321　stainless　steels　in　Solar　Salt　with　the　velocity　of　1　m/s,　2　m/s　and　3　m/s　had　been　experimentally　investigated　at　565　degrees　C　under　air　atmosphere.　The　weight　loss　data　showed　that　the　velocity　of　molten　salt　had　a　significant　influence　on　the　corrosion　process　of　316　and　321　steel.　The　corrosion　parabolic　rate　was　obtained　by　the　linear　fitting,　which　showed　slightly　increasing　with　the　increasing　of　flow　velocity.　The　macro-characteristics,　micro-morphology　and　the　thickness　of　the　multilayer　corrosion　product　were　observed　and　analyzed　by　the　SEM　and　BEI.　Meanwhile,　the　transformation　with　the　outer　elements　of　O,　Fe,　Mg　and　Na　to　O,　Fe,　Cr　and　Ni　in　the　inner　oxide　layer　was　revealed　in　the　multilayer　oxide　structure　by　EDS.　It　could　be　drawn　that　the　corrosion　resistance　of　the　two　stainless　steels　was　highly　affected　by　the　passivation　behavior　of　enrichment　of　Cr　and　Ni,　which　were　observed　in　the　inner　oxide　layer　and　confirmed　as　the　mixed　of　(Fe,　Cr,　Ni)(3)O-4　by　the　XRD.　In　addition,　the　phenomenon　of　eroding　and　accelerated　dissolution　were　observed　on　both　stainless　steels,　which　caused　the　increasing　corrosion　at　dynamic　environment.