The leakage of harmful gas occasionally happens in the production process of petroleum and chemical industry.In order to accurately determine the leakage gas types and provide emergency guidance on time,a new optical infrared imaging analysis method based on the Fourier optics is proposed for the identification of leakage gas types.The experiments also study the influence of spectral resolution,the flow of gas emission on telemetry recognition identification,and use the method to detect and identify leakage gas in an ethylene unit.The experiment and field application results show that Fourier optical infrared imaging spectrum analysis can locate the gas position quickly,and identify leakage gas type.After detecting and identifying target gas correctly,reducing the spectral resolution and gas flow has no influence on gas identification.This method is beneficial to finding safety troubles and dealing with emergency accidents.