Wet oxidation processes such as Fenton and Fenton-like have been considered to treat radioactive ion exchange resins. This investigation demonstrates the oxidative dissolution of cation exchange resin beads by using a fluidized bed Fenton process. The cation exchange resin beads were firstly saturated with catalyst (Fe(II)) in the tubular reactor with a temperature control jacket, and then initiated the oxidation with injecting the H2O2 into the fluidized bed reactor. By means of adjusting a suitable amount of ferrous ions saturated on the cation IER, the reaction can be aimed on the IER destruction rather than homogeneous oxidation. The conversion of resins to gas and soluble fragments reached 91.6% under conditions of solid loading = 117.6 g/L, 25 mL H2O2 dosage (50 wt%), FeSO4 = 10 mM at 75 °C. The fluidized bed Fenton process is efficient and ready to control for the oxidation of cation exchange resin beads in heterogeneous catalysis.