The copolymer of p-hydroxybenzaldehyde (PHB) and 4-phenolsuflonate (PHS) was synthesized using horseradish peroxidase (HRP)/H2O2 as catalyst. Firstly, PHB can react with ethylene glycol to generate p-hydroxybenzaldehyde ethylene acetal (PHBEA) so as to protect aldehyde group. Then copolymer of PHBEA and PHS was prepared by enzymatic catalytic polymerization. Finally, the copolymer of PHB-PHS was obtained by getting rid of the aldolization. Effects of monomers composition, system pH, polymerization temperature, amount of HRP and H2O2 dropwise time on copolymerization were investigated. The structure and properties of the copolymer were characterized by FTIR, NMR and GPC. The applied results show that the shrinkage temperature (Ts) of tanned leather may increase from 54°C to 74.5°C, and the copolymer has assisting dyeing and tanning effect on skin fibers.