The article discusses how to safely build a railway underground in Taipei's soft soil. The main goal is to protect existing railways and buildings during construction. The approach includes using pile foundations, underpinning slabs, and ground improvement techniques. Key findings include the importance of risk management, safety monitoring, and controlling construction noise and vibration. The design features focus on ensuring stability during deep excavation, while construction features detail the process of building new tunnels and stations. The prevention design concept can be used as a reference for future projects in similar conditions.