Recent years has seen the rapid development of rail transit and comprehensive development of underground and aboveground facilities. Against this backdrop, it is imperative to develop a suitable safe evacuation mode for ultradeep underground public spaces. From the perspective of building design, this paper combines the horizontal shelter and vertical evacuation system into a novel safe evacuation mode, consisting of horizontal evacuation, vertical escape route, emergency shelter, horizontal escape route, vertical evacuation system and exit evacuation. Then, building information modelling (BIM) was adopted to simulate the application of our safe evacuation mode to Hongtudi Station, Line 10 of Chongqing Rail Transit (CRT). The results prove that our safe evacuation mode is feasible for evacuating personnel in ultradeep underground public spaces. The research findings shed new light on the safe evacuation technology in ultradeep underground public spaces.