Abstract: Traditional building passenger flow simulation systems lack the ability to access and analyze real-time data, and the adjustment and reconstruction of simulation scenarios are cumbersome, making it difficult to adapt to the simulation analysis of large-scale public building in the new era. Therefore, a public building passenger flow simulation technology based on real-time operational data is proposed, and a prototype system is designed and developed. Firstly, based on the real-time data sources of edge-side devices, a dynamic real-time data access method for simulation requirements is proposed, innovating a modular decoupling and configurable simulation method for business needs. Finally, the visualization of passenger flow data and user interaction are realized through Web technology. The technology has been applied in the layout and passenger flow optimization project of the emergency department of a top-tier hospital, and the results show that this technology can easily realize the combination of real-time data and simulation models, improve the accuracy of the results, and also support the rapid response of simulation models to hospital business adjustments, greatly shortening the decision-making process of passenger flow simulation analysis.