Abstract: In the construction of existing building reinforcement piles in riprap silt strata, the conventional construction methods of rotary drilling, spiral digging and impact holing with slurry supporting are limited. The impact of vibrations on sensitive buildings generated by drilling cannot be ignored. In order to minimize the disturbance to existing buildings and soil layers, it is necessary to adopt a process with little interference to ensure the safety of existing buildings. Due to the flexible technology and high degree of mechanization of the full casing full rotation, combining with advantages of safe, reliability, small disturbance to the surrounding, high vertical precision of the hole and no mud pollution, this technology has been widely used in the pile foundation construction of adjacent existing buildings. The application of the full casing full rotation in the reinforcement of a project in Dalian is introduced. Focusing on the characteristics of no hole collapse and no mud during drilling, in order to improve the bearing capacity of the pile foundation and the quality of the pile body, gas lift reverse circulation and pump lift reverse cycle are applied, achieving strict sediment control requirements. It provides reference and experience for similar construction of rock-socketed pile foundation.