The invention provides a method for preparing high-purity glycerin polyethenoxy ether ricinoleate by etherifying an initiator raw material and ricinoleic acid-esterifying. The method comprises the following steps: using the glycerin as the raw material, executing the etherification reaction with ethylene oxide, and preparing the glycerin polyethenoxy ether, wherein the adding mole number of the ethylene oxide is 30-36 optimally; and according to the mass ratio of 3.79-3.83:1 of the glycerin polyethenoxy ether and the high-purity ricinoleic acid, executing the esterification reaction under the function of a specific catalyst, wherein the acid value, the hydroxyl value, the saponification value and so on of an esterification product satisfy the standard requirements. The glycerin polyethenoxy ether ricinoleate prepared by the method has the narrower chain distribution and lower esterification reaction temperature, the prepared product has light color, the product quality is easily controlled, and the stability is high.