Planning safe evacuation during disasters is extremely important, yet traditional methods are oftenrigid, expensive, and difficult to update. In this paper, we present a Digital Twin–based Disaster Evacuation Simulation System that creates a virtual version of real-world environments such as buildings. The system uses agent-based simulation implemented in Python along with real-time visualization to model how people move during emergencies like fires, floods, or earthquakes. It helps in understanding how congestion forms and how evacuation routes are used under different conditions. By testing multiple scenarios in a virtual setup, the system makes it easier to identify bottlenecks and improve evacuation strategies. Overall, this approach offers a safer and more cost-effective alternative to physical drills and supports better planning for emergency situations.