Based on the wave physical model research of sediments,we analyze scour and silt,and the stability of artificial beach for Port City Project,Colombo,Sri Lanka under two cross-sectional beaches of different slopes in the wave,different water level and return period.The results show that under the secondary wave,the beach has different degrees of erosion.The main erosion of the beach profile is generally located in the wave breaking zone below the water level,but when the wave condition increases,the erosion will extend to the area above the water level.In the experimental conditions,the higher the sea level,the higher the wave height and the period,the larger the secondary wave after the breakwater,the greater the deformation of the beach profile and the greater the erosion depth.The erosion and deposition sites of the beach profile under the secondary wave are basically similar under the two different slopes of the integrated slope and the single slope,and the section stability is equivalent.