Abstract: Aiming at the problem of bad odor appearing in some thermal recovery wells of Shengli oilfield, which affects the health of the people around them and the exploitation of heavy oil resources, the main components of bad odor were identified as methyl mercaptan and ethyl mercaptan. According to the production characteristics of oil wells, two odor additives suitable for surface pipeline and wellbore additives were developed, whose sulfur capacity and desulfurization reaction rate of the additives were also investigated. In view of the bad odor problem of a thermal recovery well, the experiments of adding chemicals to surface pipelines and wellbore were carried out comparatively. The results showed that the latter showed better economy. Field treatment was carried out in 7 wells in a block of Shengli oilfield, and the odor concentration was reduced from 150-3300 mg/m³ to below 20 mg/m³, which met the safety production requirements of oil wells and supported the safe production of thermal recovery wells.