Method of manufacturing diester-based compound

A method of manufacturing a diester-based compound in a continuous process using a reaction part in which a total of n reaction panning from a first reaction unit to an nth reaction unit are connected in series,

• wherein each of the reaction units comprises a reactor such that the reaction part includes a first reactor to a nth reactor, and
• the method comprises:
• supplying a feed stream comprising a dicarboxylic acid and an alcohol into the first reactor;
• esterifying the feed stream to prepare a reaction product;
• and
• supplying a lower discharge stream comprising the reaction product into the reactor of at least one rear reaction unit,
• wherein a conversion rate of the esterification reaction in the first reaction unit is controlled in a range of 50 to 80%,
• wherein the first reaction unit comprises m reactors including the first reactor in a state that the first reactor and the m reactors are connected in parallel, and the feed stream of the first reactor is divided by m, which is fed into each of the first reactor and the m reactors, and a flow rate of the feed stream supplied into the first reaction unit is maintained constant to control the conversion rate to be in the range of 50 to 80%.