High-efficiency composite desulphurization solvent and system and method for removing acidic gas and organic sulfur

The invention discloses a high-efficiency composite desulphurization solvent and a system and method for removing acidic gas and organic sulfur. The high-efficiency composite desulphurization solvent comprises, by mass, 70-85% of compound amine, 10-20% of a desulfurization enhancer, 10-30% of a physical solvent, 0.01-0.1% of an antifoaming agent, 0.5-2% of a benzylamine anti-oxidant and 0.5-2% of a heterocyclic amine antiseptic. The high-efficiency composite desulphurization solvent has the advantages of large acidic gas load, low sulfur content of purified gas, stable solvent performances and no corrosion on equipment, and can remove most of H2S and a large part of organic mercaptan from mixed gas. The high-efficiency composite desulphurization solvent and the system and method can greatly reduce a gas purification cost and reduce total sulfur content of the purified gas. The high-efficiency composite desulphurization solvent and the system and method can be used for removing H2S, CO2 and organic mercaptan in natural gas, petroleum refinery gas and synthetic gas.