Abstract: The long-eared owl wing surface with noise reduction characteristics was remarkable influence on its flight noise，analysing the characteristic of shape and configuration by the reverse restructure technology. The design on the bionics volute tongue will control the air current noise of the centrifugal fan. Through the experimental study, the bionics volute tongue reduce air noise of centrifugal fan in entire frequency band total acoustic pressure level LA, the average sound pressure level decreased 2.3 dB. The primary and secondary influence factors of the noise reduction effect on bionics volute tongue are: non- smooth unit spacing t, non- smooth unit integer n, highly unit h. The computer simulation analysis indicated that, the bionics volute tongue surface shape noise reduction mechanism mainly is: reduced the impact of air current to the volute tongue; causes the volute tongue surface turbulent boundary pressure oscillation to weaken and to delay the eddy shedding to fall off from the tail section of the volute tongue; causes the speed of pulsating air flow on the volute tongue surface which flows out from the air blower impeller distribute even, the speed changes suddenly reduce. The flow stability enhancement is advantageous to reduce the production of the centrifugal fan air current noise.