In　order　to　reduce　the　aerodynamic　noise　of　the　traditional　blade-type　axial　fan　and　inspired　by　the　owl　wing　profile　and　non-smooth　edge　structure,　the　thickness　distribution　at　the　40%　span　of　the　long-eared　owl　with　silent　flight　characteristics　was　extracted　based　on　the　medial　camber　line　distribution　of　the　prototype　axial　fan　as　a　benchmark.　Combined　with　the　non-smooth　structural　features　of　the　long-eared　owl　wing　edges　and　coupled　with　a　sinusoidal　sawtooth　structure　at　the　trailing　edge　of　the　imitated　owl　blade,　bionic　reconstruction　of　the　axial　fan　blade　was　performed　and　used　in　the　modified　blade　design　to　reduce　the　noise　of　axial　fans.　Based　on　the　numerical　calculation　results　of　the　internal　flow　field　of　axial　fan,　the　large　eddy　simulation　(LES)　combined　with　the　FW-H　sound　analogy　method　developed　by　Ffowcs　Williams　and　Hawkings　was　used　to　numerically　simulate　the　sound　field　characteristics　of　the　axial　fan.　The　research　results　show　that　the　overall　noise　reduction　of　the　bionic　coupled　blade　fan　is　2　dB　and　the　air　volume　is　increased　by　4.69%　compared　with　the　prototype　fan.　The　internal　flow　field　and　sound　field　of　the　fan　show　that　the　bionic　coupled　blade　makes　the　air　flow　transition　from　the　suction　surface　to　the　pressure　surface　more　smoothly,　which　not　only　improves　the　local　impact　of　the　air　flow　on　the　leading　edge　of　the　blade,　but　also　reduces　the　leakage　vortex　strength　at　the　tip　clearance.　In　addition,　the　turbulence　boundary　layer　generated　by　the　bionic　coupled　blades　and　the　degree　of　airflow　pulsation　and　airflow　unevenness　caused　by　the　wake　vortex　shedding　are　weakened,　and　both　broadband　noise　and　discrete　noise　are　reduced　in　the　low-mid　frequency　range.　Therefore,　the　bionic　coupled　blade　not　only　improves　the　local　pressure　pulsation　at　the　leading　edge　of　the　blade,　but　also　reduces　the　intensity　of　the　sound　source　at　the　trailing　edge　serration　and　improves　the　trailing　vortex　distribution　at　the　trailing　edge　of　the　blade.　©　2020,　China　Food　Publishing　Company.　All　right　reserved.