The invention provides a treatment method of thionyl chloride tail gas. The treatment method comprises the following steps: step I, performing secondary absorption for hydrogen chloride in the tail gas by controlling the consumption of the alcohol; step II, absorbing sulfur dioxide by utilizing an organic amine absorbent; and step III, after the sulfur dioxide is well absorbed, desorbing by heating the approximately-saturated absorption solution at 130 to 150 DEG C, regenerating SO2 with the purity of 95 percent or more, wherein the organic amine absorption solvent is recyclable, and the tail gas is discharged after reaching the standard; and the invention also relates to a method for manufacturing the organic amine absorbent (I). The hydrogen chloride gas in the tail gas can be converted into industrially available hydrogen chloride alcohol solution as far as possible, and the recyclable sulfur dioxide absorbent can be provided.