Abstract: Marine structures are usually subjected to the combined action of wave and current. To obtain wave-current loads acting on the structures, a simulation model for three-dimensional wave-current flumes is developed based on CFD software Flow-3D. In order to simulate the interaction between wave and current accurately, a mass source is added into the flume to generate waves, avoiding the simultaneous superposition of wave and current at inflow boundaries. The sponge layers are added at both ends of the flume using the secondary development technology of Flow-3D. These added layers are further combined with Sommerfeld radiation boundary conditions to absorb waves and to allow currents to flow through the flume. Subsequently, the developed model is used to simulate the propagation of waves, the flow field of experiments on the interactions between waves and currents, and the flow field of experiments on the interactions between wave-current and cylinder structures. The comparison shows that the developed model for a three-dimensional wave-current flume can accurately simulate the wave-current interaction and the combined action acting on structures. The model can effectively absorb waves and avoid re-reflection of waves, which can be used to study the wave-current loads acting on marine structures.