In order to effectively control the smoke and toxic gas diffusion range in cabin fire smoldering stage,the Boeing737 economy cabin model was built.The CO that was harmful to human body during the smoldering phase of the fire was taken as the research object.Under the general air supply mode and the individual air supply mode,the control effect of CO diffusion range was simulated when smouldering was in a small scale fire.NEV(net escape velocity)was used as the pollutant discharge efficiency evaluation index.It is concluded that the smoke and poisonous gas produced by smoldering fire can be controlled in the vicinity of smoldering source after increasing the individual air supply.The conclusion provides reference for controlling smoke and toxic gas in local area when a small fire smashes in the cabin of an aircraft.