Sandy beach is an important resource in coastal zone.But the erosion of sandy beach is serious under the influence of human activities and global warming.So the coastal protection is of great importance in the field of coastal engineering.Combination of artificial beach and submerged breakwater is a kind of coastal protection technology combining soft measure with hard measure.In this paper,XBeach numerical model is validated through the physical experiment result and used to the Moon Bay coastal protection engineering of combination of artificial beach and submerged breakwater.Five numerical cases are calculated with different position and different height of the submerged breakwater.Some conclusions are drawn from the analysis of the numerical results.The submerged breakwater decreases the beach erosion and is beneficial to the beach protection,and the position and height of the submerged breakwateraffect the beach protection.The further and higher the submerged breakwater is,the better the artificial beach is protected.