In recent years

the proportion of bus fire has increased significantly. Because of the dense staff and the lack of cognition about bus arson

it often causes mass casualties and injuries. This article conduct a bus combustion experiment

simulated the“5.9”school bus arson case in Weihai

which is ignited by arson in cab.The temperature and smoke changes of the vehicle during the combustion spread are observed

and the spread law of this kind of fire is summarized.The research results showed that the fire in the driver's cabin spreads rapidly

and the oxygen in the vehicle is rapidly consumed

generating a large amount of toxic gases such as CO

nitrogen oxides and sulfides after the bus is burned

. The temperature inside the vehicle exceeds 1 000 ℃ in about 3 minutes. The best time to escape from the bus is less than 30 s by breaking the window.