disclosed is a method for preparing lactide by using a solvent . according to the method , since an ionic liquid is used as a solvent in a second step in the course of preparing lactide , it is possible to secure mobility of the resulting reactant , and decrease a reaction temperature . in addition , the ionic liquid absorbs moisture generated during the reaction , and thus prevents degradation of lactide which is susceptible to moisture . furthermore , to the present method allows for the preparation of lactide successively through the continuous supply of lactic acid oligomers . because the use of an ionic liquid minimizes the contamination of a reactive group with by - products , the use of a solvent for reactor washing is unnecessary . further , owing to a high boiling point of the ionic liquid , the ionic liquid can be easily harvested and recycled .