Fe–N co-doped carbon catalyst has drawn increasing attention in the field of Fenton-like degradation of organic wastewater due to their unique structure and high activity. In this study, Fe–N co-doped carbon catalyst with high catalytic efficiency was prepared by one-step pyrolysis modified chitosan with iron ion absorption, and their property was characterized by XRD, BET, XPS and FTIR. The results demonstrated that the Fe–N co-doped carbon catalyst (αFe@CTS-T) has abundant porous structure, surface functional groups, and unique Fe–Nx configuration, which exhibited a superior catalytic ability for degradation of RhB in H2O2 system, and the removal efficiency of RhB was as high as 99.5% within 30min. In addition, further mechanistic insights by contrast and quenching experiments verified that high removal efficient of RhB mainly attribute to indirect oxidation of surface-bound radicals, 1O2 in the H2O2 system, and the pathway of radical generation was proposed.