An　absorbing　boundary　condition　based　on　the　perfectly　matched　layer　technique　is　developed.　It　is　combined　with　lattice　Boltzmann　method,　which　has　low　dissipative　and　low　dispersive　properties.　By　means　of　the　coordinate　transformation,　unconditional　stability　is　ensured.　Invoking　the　decoupling　time　integration,　we　can　solve　the　streaming　process　with　nodal　discontinuous　Galerkin　method.　Two-dimensional　Gauss　waves　and　isothermal　vortex　migration　are　used　to　study　the　effect　of　layer　thickness,　index　and　maximum　decaying　coefficient　on　the　non-reecting　performance.　Double　cavity　flow　noise　is　used　to　study　the　long　time　stability　and　the　inhomogeneous　pseudo　mean　flow.　The　result　shows　good　performance,　indicating　the　application　of　the　absorbing　boundary　condition　to　real-life　computational　aeroacoustics.　©　2019,　Science　Press.　All　right　reserved.