Abstract: The research uses sodium hydroxide to modify the printing and dyeing biochemical sludge to prepare iron-containing biochar（ISBC）,and the Mn/Cu bimetal is loaded on the biochar by impregnation and calcination method to obtain the Mn/Cu modified sludge biochar catalyst（MSDBC）is used to catalytically activate peroxymonosulfate（PMS）to degrade the hard-to-degrade polyvinyl alcohol（PVA）in printing and dyeing wastewater,and has realized the resource utilization of surplus sludge in printing and dyeing wastewater treatment and the efficient degradation of PVA. Scanning electron microscopy（SEM）,X-ray diffractometer（XRD）,Fourier infrared spectrometer（FTIR）and nitrogen adsorption and desorption isotherm（BET）are used to characterize the morphology and structure of the prepared materials,and explore the best results. The best conditions are that the metal impregnation amount is 5 mmol/g,the Mn/Cu ratio is 2∶1,the pH is 7,the peroxymonosulfate dosage is 6 mmol/L,and the catalyst dosage is 5 g/L,and under this condition,the degradation efficiency reaches 96.5%.EPR and quenching experiments show that the active species produced by MSDBC catalyzed by PMS are mainly SO₄^-·,·OH,O₂^-· and~1 O₂,and the main role is~1 O₂ and ·OH.The conversion between metals of different valence states ensure the cyclic regeneration of active sites. Repeated utilization experiments prove the reusability of MSDBC. After 5 uses,there is still a good catalytic effect. In summary,MSDBC is a sludge-based heterogeneous catalyst that effectively catalyzes the degradation of PVA in water by PMS,and has practical application prospects.