Method for purifying cationic etherifying agent via phosphate ester extraction agent

The invention discloses a method for purifying a cationic etherifying agent via a phosphate ester extraction agent. According to the method, the crude product of the cationic etherifying agent is extracted and purified by taking a phosphate ester compound as an extraction agent so as to remove epoxy chloropropane and 1,3-dichloro-2-propanol remaining in the cationic etherifying agent product. When the extraction is carried out, the final extraction agent rich in the epoxy chloropropane and the 1,3-dichloro-2-propanol is regenerated, wherein a regeneration environment is maintained as an alkaline environment by adopting an alkaline liquor; the regenerated extraction agent is recycled aiming at the extraction of the crude product of the cationic etherifying agent; and meanwhile, the recycled epoxy chloropropane is cycled into the synthesized cationic etherifying agent to be utilized. Compared with the prior art, the method disclosed by the invention is simple in process, simple and convenient to operate, less in equipment investment, economical and environmentally friendly.