Abstract: 10×10⁴ m³ floating-roof tank is widely used for oil storage in China. In order to ensure the free lifting of floating roof, it is necessary to recognize the temperature distribution of oil near the tank wall. Therefore, a 2D model of dual-deck floating-roof tank in heating process is established. The computational fluid dynamics software Fluent is used to simulate flow field of crude oil in tank and oil temperature distribution near the tank wall under 18 conditions and analyze the influence of oil level and amount of steam. Results show that the movement of crude oil in tank is composed of vortexes in different scales and thermal boundary layer with thickness of 0.2 m exists near the tank wall. This research deepens the study on heat and mass transfer in the process of tank heating and has valuable guiding significance for the safe and economic operation of large-scale storage tanks.