NOVELTY - Recycling process of vegetable oil waste clay involves: (1) waste clay oil extraction, where vegetable fats in waste clay is extracted by desorption; (2) solvent and oil recovery, where extraction solvent and oil are separated by fractionation mode; (3) pre-esterification of vegetable fats using ethanol and sulfuric acid; (4) oil transesterification involving adding ethanol and basic catalyst to pre-esterified oil and transesterifying to ethyl ester and glycerol; (5) ethyl ester/glycerol separation; and (6) ethyl ester purification.    USE - Method is useful for recycling vegetable oil waste clay (claimed).    ADVANTAGE - The method provides high value biodiesel oil that meets American biodiesel oil standard, at a conversion rate of higher than 85%, and increases the economic value of ester.    DETAILED DESCRIPTION - Recycling process of vegetable oil waste clay involves: (1) waste clay oil extraction, where vegetable fats in the waste clay is extracted by desorption; (2) solvent and oil recovery, where the extraction solvent and oil are separated by fractionation mode, and the recovered extraction solvent and oil are recycled for reuse; (3) pre-esterification of vegetable fats involving oil esterification reaction of free fatty acids in oil using ethanol and sulfuric acid at 30-65 degrees C for 30-120 minutes, where molar ratio of ethanol to oil is 6-8, the weight ratio of sulfuric acid and oil is 0.01-0.02, and content of free fatty acids in oils and fats is 2% or less; (4) oil transesterification involving adding ethanol and basic catalyst to pre-esterified oil and performing transesterification at 60-90 degrees C for 60-70 minutes, where molar ratio of ethanol to oil is 9-12, the weight ratio of basic catalyst and oil is 0.01-0.02, and the oil is converted into ethyl ester and glycerol; (5) ethyl ester/glycerol separation of transesterified product by gravity, where large proportion of glycerin deposited to the bottom by gravity is separated from the lighter weight ethyl ester; and (6) ethyl ester purification involving neutralizing the ethyl ester and glycerin, washing with water, separating oil and water, performing distillation to remove residual alkaline catalyst, ethanol and water.