To reinforce the soft soil foundation formed by dredged and filled marine sediment，experiments such as static drainage consolidation methods with surcharge preloading，and dynamic drainage consolidation methods with dynamic compaction construction are conducted in the backfill area of the coastal reclamation in Shantou City.The static-dynamic drainage consolidation method of “dewatering + surcharge loading + dynamic compaction” is used to reinforce soft soil foundation formed by marine silt and sand backfill.Through field tests，the settlement of various foundation layers，water level and pore water pressure，and soil displacement changes during construction are studied.Geotechnical tests and in-situ tests are conducted on the foundation before and after treatment，verifying the treatment effect of this method on marine silt and sand.The research shows that this static-dynamic drainage consolidation method can significantly improve the bearing capacity characteristics of the backfilled soft soil foundation，and can be widely used in soft foundation reinforcement projects for land reclamation from the sea.