Method for preparing synthetic ester base oil through step-by-step reaction

The invention relates to a method for preparing synthetic ester base oil through a step-by-step reaction. The method comprises the following steps: 1, carrying out an esterification reaction on polyoland mixed monobasic acid under the condition of excessive alcohol to synthesize polyol unsaturated ester; and 2, adding the polyol unsaturated ester into a reaction kettle containing mixed monobasicacid in a dropwise adding manner, carrying out esterification reaction under the condition of excessive local acid, mixing a small amount of catalyst with the residual unsaturated ester in the later period of the reaction, dropwise adding for catalytic esterification, and carrying out refining post-treatment after the esterification is finished, and filtering to obtain a refrigerating machine oilproduct with low acid value and good chromaticity, wherein the product yield is at a relatively high level, the method has important significance for synthesizing high-quality synthetic ester lubricating oil base oil. 本发明涉及一种分步