To mitigate the erosion of Qianshuiwan Beach affected by artificial islands and make full use of the existing shielding effect of artificial islands,two models are proposed on the southern side of the wave shadow zone behind the artificial islands.Model 1 adopts “beach shoulder sand replenishment+jetty+underwater sand bar+offshore submerged dike+sand dike”,Model 2 adopts “berm nourishment+jetty+artificial sand bars”.Numerical simulation software including Mepbay,XBeach and GENESIS are used to carry out beach profile design,stability assessment and morphological evolution prediction for the two models.Considering factors such as the protection length and secondary erosion hotspots,Model 1 is selected as the optimal basic scheme.The research finds that due to the influence of diffracted waves,there exists a problem of secondary erosion hotspots.It is necessary to change the jetty in Model 1 to an offshore submerged dike nearly parallel to the shore,and an optimized model of “beach shoulder sand replenishment+underwater sand bar+offshore submerged dike+sand dike” is proposed.The physical model test results indicate that compared with Model 1,the beach erosion rate of the optimized model decreases from 30 m over 5 years to nearly 0 m within one year.The proposed model can serve as a reference for beach restoration projects in similar coastal areas.