The gas collection hood is a crucial component of the waste gas treatment system, and its collection efficiency directly impacts the treatment effectiveness. To clarify the relationship between flue gas temperature and the collection efficiency of the gas collection hood, this study took seven plastic product enterprises in Cang County as the research subjects. The point source correction method was employed to deduce the unorganized emission source strength, and the collection efficiency at different temperatures was analyzed. The results showed that within the temperature range of 120~210 ℃, the collection efficiency decreased from 95% to 68%, exhibiting a strong negative correlation (r=-0.977). The regression equation is collection efficiency = -0.00341 × temperature + 1.366. The study suggests that enterprises should pay attention to the impact of flue gas temperature and optimize the design of the gas collection hood.