The present invention relates to a preparation method for high purity fluoroethylene carbonate. The preparation method comprises the following steps: 1) reacting raw material chloroethylene carbonate with liquid hydrogen fluoride to produce a mixture; 2) adding a metal oxide into the mixture for an acid removal reaction and filtering to produce a filtrate; 3) adding a solvent into the filtrate and mixing, cooling for crystallization to produce fluoroethylene carbonate crystals, and removing water to produce high purity fluoroethylene carbonate. The preparation method of the present invention for high purity fluoroethylene carbonate uses chloroethylene carbonate and anhydrous liquid hydrogen fluoride as raw materials for a liquid-liquid reaction, then high purity fluoroethylene carbonate is prepared via the acid removal reaction, cooling for crystallization, and warming for water removal, and the purity of the product produced is 99.5% or more. The preparation method has simple process control and few side reactions, is easy to purify, high in reaction product purity, and inexpensive, and favors industrial production.