Digital twin technology was applied to address issues of low digitalization, invisibility of underground operations, and uncontrollable schedules in deep foundation reinforcement. A digital twin system was designed based on geological conditions and monitoring requirements. The system was developed through model establishment, data acquisition, and dynamic mapping. In the model establishment stage, a digital twin model of the construction process was constructed based on multi-dimensional data. In the data acquisition and processing stage, real-time data was obtained through a sensor network, and then corrected and integrated. In the dynamic mapping stage, construction data and the model were synchronously mapped to achieve all-round digital monitoring of the foundation reinforcement construction process. The system was applied to the south anchorage of the Zhang jing-gao Yangtze River Bridge’s north channel bridge. Results showed that all engineering parameters met or exceeded design requirements. Efficiency and quality were improved, and underground operations were visualized. Through real-time monitoring and dynamic adjustment of engineering parameters, the construction period was shortened, the reliability and controllability of deep foundation reinforcement construction were improved, and the digital level of the engineering project was comprehensively enhanced.