The　aerodynamic　noise　of　a　cross　flow　fan　with　uneven　blade　spacing　in　room　air-conditioner　was　simulated　by　computational　aerodynamic　acoustics　(CAA)　method.　It　is　detailed　to　analyze　the　vorticity　distribution　of　the　flow　field　and　the　power　spectral　density　of　measured　points＇　pressure　fluctuations,　and　the　results　demonstrate　the　non-uniform　impeller　used　in　this　paper　can　significantly　improve　internal　flow　characteristics.　Thus　the　broadband　noise　got　reduced.　©　2016　Trans　Tech　Publications,　Switzerland.