[Objectives]The problem of noise caused by an unsteady flow field around a surface ship is a difficulty facing the stealth design of ship hulls,in which the existence of the free surface makes it different from submarine hydrodynamic noise calculation. To solve this problem,[Methods]the Volume of Fluid(VOF)method and SST k-ωturbulence model are combined to simulate the unsteady flow field of the hull,and the free surface is given an air acoustic impedance to simulate the absorption boundary. The pulsating pressure of the hull surface is used as the source of the noise,and the underwater radiation noise of the surface ship is calculated with the acoustic finite element method.[Results]The results show high agreement with the experimental results and previous simulation results. The noise sources are mainly concentrated at the bow of the hull. [Conclusions] The results show that this calculation method can accurately simulate the flow field and sound field of a surface ship,and it can provides valuable reference for the acoustic stealth design of surface ships.