The major source of raw materials for the experiment was Psyllium fiber (PF), an insoluble diet fiber derived from Psyllium seeds. The key composition, particle size and specific surface area, microstructure by SEM, FTIR, and X-ray diffraction of PF were all examined concerning the impact of irradiation doses of 0, 5, 10, and 20 kGy. Results implied that when the dose of γ-irradiation was 20 kGy equated to the untreated one, the concentrations of cellulose, hemicellulose, and lignin in PF fell by 13.74, 23.41, and 16.6%, orderly, and the volume particle size of PF declined by 130.44 μm. The specific surface area expanded by 83.28 m2/kg while the crystallinity slightly declined. Pores and erratic particles could be seen on the PF's microstructure surface after exposure to γ-irradiation. According to the IR-spectrum data, the hemicellulose and lignin in PF were eliminated by γ-irradiation. These results indicate that the structural properties of PF may be significantly affected by γ-irradiation. When the radiation dosage was 10 kGy, PF had the greatest oil-holding, H2O-holding, and swelling capabilities (8.35 g/g, 21.0 g/g, and 9.35 mL/g, respectively), and it also had the strongest adsorption capacities for sodium nitrate, cholesterol, and glucose. These results imply that γ-irradiation improves the PF's functional properties. This study's use of γ-irradiation technology as a pre-treatment provided a theoretical framework for the use of PF in food processing.