Abstract: Accurate quantification of volatile organic compounds emissions from floating roof tanks is conducive to energy saving and emission reduction in the petrochemical industry, reducing air pollution and improving the environment. By analyzing the emission mechanism of the floating roof tank, a certain inner floating roof gasoline tank was taken as an example to calculate edge sealing loss, hanging wall loss, floating roof attachment loss and floating roof aperture loss by means of the AP-42 emission calculation formula recommended by the American EPA, and the change of the loss in different conditions was compared. According to the influence factors of VOCs emission from floating roof tank, it is suggested that the VOCs emission can be effectively reduced by adding secondary seal, adopting double-deck floating roof, selecting anti-corrosion coating on the tube wall rationally, adopting spraying water cooling to the tank and setting up a cap. The research results can be used as the guide for the energy saving and emission reduction of enterprises.