The FEM\BEM acoustic-vibro-coupling method was applied to study the effect of blade outlet angle to centrifugal pump noise caused by the hydrodynamic forces. Firstly, the large eddy simulation method is used to solve the transient flow field of the pump, and the volute surface dipole was obtained. Secondly, the modal of the pump housing structure is analyzed using the finite element method (FEM). Lastly, the acoustic-vibro coupling module of the Virtual Lab software was employed to study the interior sound fields of the pump caused by the unsteady flow. By comparing the computational results with experimental ones, the validation of the LES combined with the FEM\BEM methods for centrifugal pump noise computation was verified. On this basis, the outer sound fields were investigated, and the effect of blade outlet angle to outer sound fields was studied. The results show that the sound power at the BPF becomes large as the blade outlet angle increase; the blade outlet angle should be at suitable range to ensure a lower noise level at low flow rates.