The feedwater of the fourth-generation nuclear power unit is prone to flow accelerated corrosion (FAC) under the condition of all volatile treatment (reduction) (AVT(R)), resulting in the deposition of magnetic Fe3O4 at the inlet throttle hole of the steam generator, causing blockage of the steam generator tubes and affecting the safe and stable operation of the nuclear power unit. Oxygenation treatment (OT) of feedwater is currently the most effective method for inhibiting flow accelerated corrosion. In order to alleviate the problem of blockage of the inlet throttle hole of the steam generator in the fourth-generation nuclear power unit, a feedwater oxygenation treatment method suitable for the fourth-generation nuclear power unit was developed. By collecting and organizing data on water quality, operating parameters, materials, oxygenation methods, oxygenation positions, oxygenation concentrations, etc. of 30 thermal power once through boiler units that have already implemented feedwater oxygenation treatment, and comparing them with the water quality, operating parameters, materials, etc. of the secondary circuit of the fourth-generation nuclear power unit, the advantages and disadvantages of the four feedwater oxygenation methods in terms of safety, economy, control accuracy, and operational reliability, as well as their applicability in the fourth-generation nuclear power unit, a scientific and reasonable feedwater oxygenation treatment method for the fourth-generation nuclear power unit was proposed to guide the operation of the fourth-generation nuclear power unit. Provide an optimal solution for feedwater oxygenation in fourth-generation nuclear power units.