Abstract: Aiming at solving the problem of low mass transfer efficiency and easy generation of disinfection by-products of traditional ozonation technology, ozone micro-nanobubbles combined with H₂O₂ oxidation system was adopted to improve mass transfer efficiency and oxidation capacity and reduce the production of disinfection by-products. The effects of ozone flow rate, H₂O₂ concentration, and common groundwater geochemical parameters on the degradation of 2-chlorophenol were investigated, and the application of the O₃-H₂O₂ system to typical environmental pollutants was studied. The experimental results showed that the ozone utilization rate was the highest when the ozone rate was 40 mg/min; O₃-H₂O₂ system had the best degradation efficiency on 2-chlorophenol when H₂O₂ concentration was 0.5 mmol/L and pH=9; the existence of Cl⁻, CO₃ ²⁻/HCO₃ ⁻ and natural organic matter inhibited O₃-H₂O₂ system; O₃-H₂O₂ system had good degradation effects on four typical environmental pollutants including antibiotics, chlorophenols, chlorinated hydrocarbons, and nitro-containing organic compounds.