Abstract: Abstract: In order to reduce casualties and improve rescue efficiency of fire in "three-in-one", a self-built house was selected as test site of fire simulation experiment. The fire development process, the temperature curves at different positions of the fire scene, the fire smoke flow trajectory, the on-site damage after the fire and the burning of the dummy model are systematically studied under three fire conditions. The results show that the smoke temperature in the stairwell on the low floor can reach more than 350 ℃ under three fire conditions. When the roof door and the room door and window are used as the vents, the fire develops and spreads rapidly and flashover and backfire appear, the chimney effect is easy to occur and the smoke flows towards the vents. When the roof door is ventilated, the temperature of the fire point exceeds 1 100 ℃, the internal temperature of the fire-fighting protective clothing exceeds 200 ℃, and the breathing mask is burned. When the building is completely closed, the hot smoke flows in a two-way airflow path after gathering. The temperature of the fire initial point exceeds 600 ℃. According to the research results of real fire, technical and tactical suggestions for fire fighting and rescue are put forward including the aspects of fire environment judgment, risk prevention and control, internal attack technology in different scenes, etc.

Key words: Key words: three-in-one building, firefighting, flashover, technical tactics