A review.The biol. method has successfully replaced the chem. method to produce long-chain dicarboxylic acids.Heavy components containing dibasic acids are produced in the extraction and purification of long-chain dicarboxylic acids in biol. processes.Due to the complex composition, extraction of mixed dibasic acids from heavy components is a tech. difficulty in the industry.This article aims at the mixed dibasic acids extraction technol. for heavy components.First, the heavy component composition and the source of impurities were analyzed, and then the different extraction technologies and their tech. principles were explained, while the advantages and disadvantages of each extraction method were compared.The results showed that the aqueous phase salt-acidification crystallization method was simple to be operated and contained no solvents.However, it consumed acid and alkali and generated more salt which needed to be treated.Organic solvent crystallization could be achieved by cooling crystallization after concentrationThe method was compatible with the main production line process, and the amount of workload of equipment modification was small.The extraction method needed a solvent.Some special solvents could sep. impurities such as pigments, but the solvent separation should be considered.It was difficult for chromatog. separation to achieve high resolution, while the operation of the column was complicated, which was not suitable for large-scale productionThe key of the esterification separation method was to connect the esterified product to the market.Finally, based on the existing technol., it was proposed that future research needed to focus on the extraction process innovation, separation equipment processing and strengthening environmental protection measures.