The horizontal twin-plate breakwater is an advanced permeable structure.Since the wave energy is mainly concentrated on the surface of water body,the breakwater structure can be designed accordingly to realize the function of wave reduction.Based on FLUENT platform,the numerical simulation method is used to compare the action results of five kinds of wave with different incident period,and the wave reduction characteristics and wave pressure distribution of horizontal twin-plate structure are studied.The results demonstrate the structure's effective wave reduction within the tested range,revealing the relationship between the structure's wave reduction efficiency and the relative plate width.Additionally,the wave pressure distribution on the structure's surface at representative time points is analyzed,establishing a connection with the relative plate width.The study of the flow field morphology around the structure provides insights into the wave reduction mechanisms at play.