Abstract: In order to study the effect of sound waves on flow around a single cylinder and its heat transfer characteristics, a two-dimensional mathematical model of multi-physical coupling flow field, sound field, and convection heat transfer is established, and the finite element software COMSOL is used for numerical simulation. The results show: (1) when the frequency f =50 Hz and the sound pressure level L_SP=123－149 dB, the Strouhal number Sr decreases and the cylindrical surface pressure coefficient C_P increases as L_SP increases; (2) When L_SP=143 dB and f =20－80 Hz, both Sr and pressure coefficient C_P increase with the increase of f; (3) Under the condition of having sound wave action (f =50 Hz and L_SP=143 dB) or no sound wave action, the drag coefficient C_DF and lift coefficient C_DL all change periodically, but the amplitude under sound wave action increases; (4) The effect of acoustic waves can promote heat transfer on the cylindrical surface, but when L_SP>143 dB, the local Nusselt number Nu_θ on the cylindrical surface begins to decrease. The research results provide a theoretical research foundation for enhancing heat transfer around a cylinder.