Abstract: An underwater ellipsoid-shaped sonar cavity model was created by SEA method.The separation position of turbulent boundary layer was calculated with different flow speeds by CFD software,and the spatial distribution o f non-uniform for turbulent fluctuating pressure was considered.This paper analyzed the influence of flow speeds and different absorption and damping coatings on the sonar flow-induced self noise.The results of theoretical evaluation for absorption coating agreed with the numerical results.It shows that the greater flow speed is,the greater sonar self noise is.And the smaller percentage the acoustic window area accounts for,the better performance noise reduction for absorption and damping coating will.The results could support the prediction and control of flow-induced noise for underwater sonar cavity.