Based on the smoothed particle hydrodynamics (SPH) method modified by corrective smoothed particle method (CSPM) and Riemann solutions，a numerical flume model is built to simulate the interaction between waves and perforated caisson，and the accuracy is also verified by comparing theoretical solutions with numerical results.The influences of the reflection coefficient Kr of perforated caisson with double-layered and the wave pressure p of static water level are studied from the factors of relative width B/L，relative wave height H/L and relative water depth d/L.The complicated process of water particles entering and leaving the wave dissipation chambers is also studied.The results show that there is a nonlinear relationship between the relative width B/L and the wave pressure p under the research conditions，and the reflection coefficient Kr decreases with the increase of the relative width B/L.Relative wave height H/L has little effect on wave pressure p and reflection coefficient Kr.With the increase of the relative water depth d/L，the wave pressure p gradually decreases，and the reflection coefficient Kr shows a nonlinear characteristic of decreasing first and then increasing.The motion of water particles in the front chamber is more intense than that in the back chamber，the horizontal velocity changes more than the vertical velocity，and the water particle velocity changes obviously near the perforated position.