The invention relates to an extraction method and an extraction agent for a denitration procedure in an H
acid production process, and belongs to the technical field of the organic
chemical industry.The extraction method comprises the following steps: firstly, preparing the extraction agent which comprises a
solvent, a diluting agent and a co-
solvent, wherein the co-
solvent is 2-ethylhexylphosphoric acid mono-2-ethylhexyl ester, the solvent is a
tertiary amine type solvent, and the diluting agent is one or more of sulfonated
kerosene,
benzene and
toluene; then, extracting denitration substances by adopting the extraction agent, and forming a complexation layer and an inorganic acid aqueous layer after extracting; and applying the inorganic acid aqueous layer to an H acid segregation procedure, performing back extraction on the complexation layer, adding a back extraction agent until the pH of an organic aqueous phase formed by back extraction is 7-9, forming trisodium salt from the denitration substances, standing the trisodium salt to be layered to obtain an
organic layer, and applying a solvent layer. The extraction agent does not react with the denitration substances, so that the complexation effect is good, the layering is easy, and the loss of the extraction agent is greatly reduced; and by applying the extraction method and the extraction agent to H
acid production, generation of a large amount of
wastewater is avoided, a large amount of
ammonia is saved, and thus the production cost is lowered.