Abstract: Bamboo natural fiber is a safe and non-toxic green resource, but its utilizaiton is restricted to some extent. In this experiment, ⁶⁰Co-γrays was used to irradiate bamboo fiber to directionally change its structure and physical and chemical properties, so asa to improve its utilization value and broaden its application range. Infrared spectroscopy technology was used to analyze the functional group changes of Neosinocalamus affinis bamboo fiber treated with different irradiation doses. The changes of hydration (average water absorption, binding water capacity, water holding capacity), expansion force, and heavy metal ion adsorption performance were studied. The results showed that irradiation treatment did not change the characteristic peak type, position and number of peaks of bamboo fibers, but only changed intensity of some characteristic absorption peaks. However, after irradiation modification, the hydration, expansion force and heavy metal ions adsorption of bamboo fibers all increased, reaching the maximum vaule when the irradiation dose was 5 kGy: the average water absorption rate reached 689%, the water holding capacity reached 7.49 (g·g⁻¹), and the combined hydraulic force reached 6.84 (g·g⁻¹); 4.03 (mL·g⁻¹); the highest Ni²⁺ removal rate in water was 41.0%, while the Cu²⁺ removal rate was as high as 81.8%. This indicated that ⁶⁰Co-γ-ray irradiation could improve some physical and chemical properties of natural bamboo fiber. When the irradiation dose continued to increase to 10 kGy, its hydration, expansion force and heavy metal ion adsorption would decrease.