To　study　the　influence　of　dorsal　pressure　difference　on　the　atomization　characteristics　of　a　pressure　swirl　nozzle,　the　spray　cone　angle,　Sauter　mean　diameter,　speed　of　the　spray　particles,　and　their　radial　and　axial　distributions　were　experimentally　studied.　Results　show　that　the　spray　particles　and　spray　cone　angle　increase　with　increasing　dorsal　pressure　difference,　while　Sauter　mean　diameter　decreases.　The　atomization　parameters　vary　less　than　5%　when　the　dorsal　pressure　difference　is　higher　than　0.30　MPa.　The　spray　droplet　velocity　decreases　with　the　increase　of　the　axial　distance,　while　the　Sauter　mean　diameter　increases　and　then　drops　off　with　increasing　axial　distance　when　the　dorsal　pressure　difference　is　fixed　to　0.30　MPa.　The　rises　in　Sauter　mean　diameter　and　spray　cone　angle　occur　with　increasing　radial　distance　along　the　radial　direction.　©　2018,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.