Abstract: The CCJ desulfurization and decarbonization composite solvent was prepared by joining a variety of active agent, defoaming agent and corrosion inhibitor with certain proportion into 45%(mass fraction) MDEA solution. Taking H₂S, CO₂ and organic sulfur content in the purified gas as evaluation index, the purification ability of CCJ composite solvent to high hydrogen sulfide natural gas and the foam resistance ability were studied on the pilot scale experiment. The results showed when the absorbent temperature is 50 ℃, the gas to liquid ratio is 500 m³/m³, the regeneration temperature is 108 ℃, the composite solvent had excellent purification capacity; when the volume fraction in sour gas is 7.12% of H₂S, 4.57% of CO₂ and mass concentration 413.77 mg/m³ of organic sulfur, and the absorbent pressure is 6.0 MPa, the purified gas could reach the standards with mass concentration of H₂S≤6 mg/m³, volume fraction of CO₂≤0.5% and mass concentration of organic sulfur≤16 mg/m³. Meanwhile, the composite solvent exhibits an excellent foam resistance capacity.