The“South China Sea I” has been submerged for more than 800 years,and the porcelain on it has been corroded by seawater,marine organisms and marine sediments,leading to diseases like salination, soil erosion,defects etc. In this study two pieces of porcelain from different kilns were selected,and their states of preservation, craftsmanship and disease were studied. Chemical solvents like alcohol, acetone and citric acid as well as ultrasonic cleaning were used to remove the absorbed salt and surfacesoil erosion of the porcelains.Following the principle of using identifiable restorations and leaving the cultural relics unchanged, Epoxy glue, talcum powder and acrylic resin paint were used to repair the porcelains, thus obtaining a satisfactory restoration result.The research techniques described in this paper are beneficial for the longtermpreservation,exhibition and display of the objects, and, in addition,provide a reference for the preservation and restoration of a large number of porcelains currently in the same conservation environment and having the same diseases.