Display omitted •Novel magnetic pullulan (MP) hydrogels were designed.•These prepared MP hydrogels were for the first time used as Fenton-like catalysts.•MP hydrogels exhibited excellent degradation activity, reusability and stability.•Degradation mechanism for tetracycline hydrochloride in our MP3/H2O2 system was proposed. Magnetic nanoparticles that can be employed as Fenton-like catalysts Fenton-like catalysts are attractive materials for degrading antibiotics. In this study, we facilely prepared novel magnetic pullulan (MP) hydrogels by doping modified magnetic nanoparticles into pullulan matrices, which could enhance catalytic degradation performance and strengthen the stability of resulting hydrogels. This is the first time that MP hydrogels have been fabricated successfully and used as Fenton-like catalysts for tetracycline hydrochloride (TCH) degradation. MP hydrogels were characterized and their catalytic TCH degradation abilities were also investigated. The optimized conditions (pH value, Fe3O4 content, H2O2 content and TCH concentration) for TCH degradation were investigated. The optimized system showed excellent degradation efficiency for TCH. Further, the degradation mechanism was comprehensively studied. Finally, synthesized MP hydrogels showed impressive reusability and stability in the cycle experiment. Thus, our findings would open new possibilities to develop magnetic hydrogels in eliminating antibiotic contaminants.