In order to study the characteristics of bearing capacity of rock-socketed piles covered by overfilled soil, this paper carries out static compression tests on two rock-socked piles in the project of Nanning No.3 Middle School international school, and analyzes the variation law of axial force, lateral friction resistance of pile body and resistance of pile tip with load. The test results show that the lateral friction resistance of the soil layer around the pile and the end bearing capacity of the pile tip together constitute the bearing capacity of the rock-socketed pile with the vertical load. As the depth increases, the axial force of the test pile gradually decreases. When the load on the pile top increases, the corresponding axial force decreases faster. In overfilled soil, pile filling coefficient is relatively large, and the end resistance of medium-weathering siltstone occupies a small proportion of the total loading load. Therefore, during the construction process, the mud thickness of the mud retaining wall should be strictly controlled, and the detection of sediment thickness should be strengthened. it is suggested that the grouting technology of pile bottom should be adopted to give full play to the resistance of pile tip.