Hydrological characteristics such as waves, tides, currents, and meteorological features such as weather and wind, as well as geological structure were collected. Through the field trips of Kongtong Island, observations of its base rock coast, measurement of beach slope and beach gravel particle size, gravel and sandy samples was collected in the intertidal zone of west beach, east beach, and north beach of Kongtong. Particle size analysis and roundness calculation were carried out to verify whether they were consistent with the oceanographic data collected from Kongtong Island. The results showed that the north beach was mainly gravel, the west beach was a mixture of sand and gravel, and east beach was a sandy sediment. The particle sizes and roundness of different samples showed that north beach had the strongest hydrodynamic conditions, followed by the west beach, and the east beach had the weakest hydrodynamic conditions. This had a direct relationship with perennial wave direction and wind direction. Full understanding of the oceanographic characteristics of Kongtong Island is of great practical significance for the better development and utilization of Kongtong Island and the rational use of its geographic location for tourism and recreation.