Post-earthquake fires in populated stations pose a significant threat to passenger safety, necessitating the implementation of efficient emergency evacuation procedures to adequately safeguard lives and property. Utilizing Building Information Modeling (BIM) and Pathfinder, this study innovatively delves into the emergency evacuation optimization measures under a post-earthquake fire. Three pivotal research questions are explored: a comparative analysis of the Required Safe Egress Time (RSET) versus the Available Safe Egress Time (ASET) to evaluate the safety of evacuation procedures; a focused examination of critical time points and influential factors during evacuation process; and the formulation of optimization measures to enhance evacuation efficiency. The Beijing Xiyuan rail transit station was chosen as a case study, with four post-earthquake fire scenarios simulated. Additionally, the impact of obstacles and injured personnel resulting from the earthquake was considered. The results show that: (1) During evacuations, critical issues arise at specific time points. The entrances of escalators/stairs, turnstiles, and exits are key sites, where congestion becomes critical issues. (2) Evacuating rescue personnel through public non-paid areas saves 9.1 % of the evacuation time compares to crossing turnstiles. (3) The most impactful measures for optimizing evacuation is that trains arrive in only one direction, followed by the deployment of evacuation guidance. Thus, key control time points and optimization measures for the evacuation process of complex urban rail transit stations can be obtained. The findings provide insights and guidance for optimizing emergency evacuation in rail transit stations to mitigate post-earthquake fire risks and ensure public safety.