Abstract: In order to explore the distribution characteristics of flow and hydraulic noise in the conduit of a vertical axial-flow pump device, the flow field and sound field in the pump device were numerically solved by the combination of computational fluid dynamics（CFD） and computational acoustics（CA）, and the effectiveness of the numerical results was verified by physical model tests. The results show that the internal flow pattern of the elbow inlet conduit is relatively smooth and the velocity distribution is relatively uniform. Affected by the residual circulation of the guide vane, the velocity distribution of the water flow in the 90° elbow is uneven, and the streamline moves spirally into the straight outlet conduit, resulting in the disorder of the internal flow pattern. The peak values of sound pressure level and sound pressure intensity in the conduit mainly appear at the blade frequency and its octave frequency, indicating that the rotation of the impeller is an important reason to induce the conduit noise. The maximum value of the total sound source intensity of the elbow inlet conduit is located at the outlet, which is 254.8 dB, and the maximum value of the total sound source intensity of the straight outlet conduit is located at the transition section of the structure, which is 248.8 dB. The change in the flow cross-sectional area of the conduit has an important impact on the component variation of flow velocity. The greater the component variation of flow velocity, the greater the total sound source intensity. Therefore, the total sound source intensity in the transition section of straight outlet conduit structure increases by 2.6% relative to the inlet. When optimizing the design of conduit of the vertical axial-flow pump device, the change of conduit structure should be reduced.