Abstract: Fire spread characteristics, heat release rate, temperature change etc. have been studied to explore the the changing rules of the fire spread characteristics under different flow velocities in the brick-wood structured ancient buildings. Taking Sanyuan Town God's Temple, a typical brick- wood structure system in China, as an example, with the help of BIM, fire scenarios have been developed to do the fire simulation analysis. The results show that the flame spread fluctuates periodically. within certain areas, the higher the flow velocity, the shorter time for the heat release rate to reach the peak, the shorter time interval between the primary peak and the second peak, and the shorter time to reach the flashover. The buoyancy of hot smoke will cause the flame to spread upward to the roof, where the temperature is the highest, and the structure there will be endangered more easily.

Key words: ancient building, wood structure, model transformation, flame spread, flashover