Endowing hydrophobic polyester chopped fiber with hydrophilic properties can expand its application value. This article proposes that gallic acid and ethylenediamine are co-deposited on the surface of polyester chopped fibers by Michael addition or Schiff base reaction in alkaline Tris buffer. The dynamic contact angles of polyester chopped fibers before and after modification were measured, and the micro morphology of the fibers was observed by scanning electron microscope (SEM),Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) The changes in the surface structure of the fibers were characterized. Finally, the polyester chopped fiber and hardwood pulp were used to make paper before and after the modification. The pore size distribution changes and air permeability of the paper were measured, and the physical properties of the paper were tested. The results show that there are a large number of hydroxyl groups on the surface of the polyester chopped fiber after co-deposition modification, nitrogen is generated on the surface of the fiber, and the surface roughness is improved. Compared with the unmodified polyester chopped fiber, the modified polyester The contact angle between chopped fiber and deionized water is reduced by 57.2?, which significantly improves the hydrophilicity of the fiber. Compared with the unmodified fiber paper, the tensile strength of the modified fiber paper is increased by 35.2%, and the wet strength is increased by 43.3. %, the air permeability increased by 11.1%, the pore diameter increased by 24%-30% within the same pore diameter range, and the fiber dispersion was significantly improved. The results of this research can produce polyester fibers with excellent hydrophilicity and can be used in high-performance paper applications.