The attenuation process of the oxygen reduction reaction (ORR) catalytic performance for Fe SAC@G catalysts under different discharging conditions, including KOH concentrations, solution temperatures, and discharging potentials, was investigated by electrochemical measurements. The ORR catalytic activity attenuation resulting from the change in KOH concentration and temperature becomes apparent in a negative discharging potential range and elevated discharging temperature. In addition, the more negative discharging potential significantly causes the ORR catalytic activity attenuation. Scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy analyses indicate that, with the prolongation of the discharge time, the nanocolumns of the as-prepared catalyst gradually dissolve, while a flowerlike discharge byproduct composed of elements C and N keeps growing on the surface of the catalyst. The weakest Fe–N bonds first break, resulting in the attenuation of the ORR catalytical performance. Then, the weak C–Cunit bonds connecting the structural units of the catalysts break, leading to the gradual collapse in the structure of the catalysts. The Fe–N4 coordination structure gradually transforms into Fe–N3, Fe–N2, and Fe–N coordination structures. Based on the analyses combined with the density functional theory (DFT) calculations of bond strength, a discharge attenuation mechanism of the structural collapse of the catalyst for the formation of the discharge byproduct with ring structure is proposed.