【Purposes】 The low degradation efficiency of anode materials in printing and dyeing wastewater has led to low industrialization process.【Methods】 SnO2-Sb-Co3O4@GF nanocomposite electrode materials with different Co3O4 doping contents were prepared by multiple dipping and thermal decomposition method. The morphology, crystal phase, and surface elements of nanocomposites were characterized by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The free radicals produced by electrolysis of water were identified by chemical trapping agent method. 【Findings】 The results show that Co3O4 was uniformly doped into SnO2- Sb solid solution, and a nanocrystalline thin layer was formed on the surface of carbon fiber. Among all prepared electrodes, SnO2-Sb-Co1%@GF exhibited small, uniformly distributed, and dense particle size; During the electrolysis of Na2SO4 aqueous solution, the electrode releases a large number of strong oxidizing free radicald such as ·OH, SO4·-, ·O-2, and 1O2, in which 1O2 plays an important role in the degradation of rhodamine B (RhB) in wastewater. 【Conclusions】 The electrochemical characterizations of linear sweep voltammetry, cyclic voltammetry, and AC impedance show that the electrode had the highest exchange current density, voltammetric charge, electrochemical active area, and low AC impedance, showing outstanding catalytic activity of water electrolysis.