In order to study the mechanism of dissolved oxygen content on the surface corrosion behavior of Fe-based heat transfer, the first principle is used to study the adsorption of O2 monomolecular, H2O monolayer and dissolved oxygen system on Fe-based heat transfer surface. The GGA/PBE approximation is used to calculate the adsorption energy, state density and population change during the adsorption process. Calculations prove that when the dissolved oxygen is adsorbed on the Fe-based surface, the water molecule tends to adsorb at the top sites, and the oxygen molecule tends to adsorb at Griffiths. When the H2O molecule adsorbs and interacts on the Fe (001) surface, the charge distribution of the interfacial double electric layer changes to cause the Fe atoms to lose electrons, resulting in the change of the surface potential. When the O2 molecule adsorbs on the Fe (001) crystal surfaces, the electrons on the Fe (001) surface are lost and the surface potential increases. O2 molecule and the surface of the Fe atoms are prone to electron transfer, in which O atom's 2p orbit for the adsorption of O2 molecule on Fe (001) crystal surface play a major role. With the increase of the proportion of O2 molecule in the dissolved oxygen water, the absolute value of the adsorption energy increases, and the interaction of the Fe-based heat transfer surface is stronger. This study explores the influence law of different dissolved oxygen on the Fe base heat exchange surface corrosion, and the base metal corrosion mechanism for experimental study provides a theoretical reference.