In order to explore the influence of eccentric structure on the heat transfer performance of carbon dioxide tubular the air cooler, the concentric rectangular spiral casing and eccentric rectangular spiral casing air cooler were established based on Fluent software, the temperature nephogram, velocity nephogram and specific heat capacity nephogram under the same operating conditions were compared, and the convective heat transfer coefficient, turbulent kinetic energy and pressure curve were analyzed. The numerical simulation results show that compared with the concentric casing air cooler, the cloud image of the eccentric casing air cooler is more skewed than that of the concentric structure, and the average convective heat transfer coefficient and turbulent kinetic energy increase by 1299% and 1538%, respectively, compared to the concentric structure. At the same time, the maximum pressure drop increases by 1485%, and the overall heat transfer performance of the eccentric casing is better than that of the concentric casing. The eccentric sleeve type air cooler structure is superior to the concentric sleeve type, which provides scientific basis for the design, operation, and thermal efficiency improvement of rectangular spiral wound gas coolers in supercritical CO2 heat pumps, and has important practical significance for the application of high-efficiency heat exchangers.