Objective With the rapid development of urban rail transit in China, its characteristics of large passenger capacity and enclosed spaces, while providing convenience, also pose significant safety risks when facing sudden incidents such as fires, terrorist attacks, and natural disasters. It is aimed to systematically elaborate on the emergency evacuation mechanism as an effective measure to address the above threats, highlighting its critical importance in safeguarding passengers' lives and property and maintaining the stable operation of the system. It further analyzes the constituent elements and operational processes of the mechanism, in order to provide a theoretical reference for enhancing the safety resilience of rail transit systems.

Method Through theoretical analysis, the safety risks of rail transit and the diverse impacts of sudden incidents are first examined. Subsequently, the construction of the emergency evacuation mechanism is elaborated in detail from four constituent elements: first, formulating refined evacuation plans based on station types and architectural structures; second, organizing and training staff professionally and establishing external coordination; third, ensuring the completeness and effectiveness of evacuation facilities （such as passages, signage, and fire protection equipment）; fourth, building an accurate information dissemination and guidance system. Meanwhile, the complete operational process of the mechanism—from monitoring and early-warning, initiation and execution, coordination and control, to reviewed. Additionally, optimization pathways are explored by drawing on domestic and international experience, applying new technologies such as the Internet of Things and artificial intelligence, and improving legal and regulatory frameworks.

Result & Conclusion  The emergency evacuation mechanism is a complex system engineering endeavor characterized by multi-element coordination and multi-stage integration, and it constitutes an indispensable key component of the rail transit safety consequences of sudden incidents. Therefore, continuously improving its constituent elements, constantly optimizing its operational processes, and actively integrating advanced technologies and management experience are inevitable requirements and strategic directions for fundamentally enhancing the capability of China's rail transit system to respond to emergencies and safeguard urban public safety.