Sludge, as the residue after sewage treatment, contains various heavy metals, organic substances and microorganisms, which is seriously harmful to the environment and human health. Sludge-derived biochar-based materials exhibit promising application prospect in the field of advanced oxidation processes for water remediation due to the favorable porous structure, excellent surface charge distribution and abundant oxygen-containing functional groups. At present, multiple sludge biochar-based catalysts with high catalytic activity was employed successfully in the photocatalysis, persulfate activation and Fenton oxidation systems. Herein, the preparation methods of sludge biochar-based materials were summarized systematically. In addition, the degradation efficiencies and internal mechanisms of sludge biochar-based catalysts in different oxidation systems were analyzed comprehensively. However, the stability of sludge biochar-based catalysts should be enhanced to prevent the release of heavy metals and other contaminants in the future. Meanwhile, the catalytic activity and recyclability of sludge biochar-based catalysts in a continuous-flow reactor should be investigated to enhance the practical application potential.