The invention provides a treatment method for reducing the pour point of natural ester insulating oil, and belongs to the technical field of deep refining of natural ester insulating oil. The treatment method for reducing the pour point of the natural ester insulating oil comprises crystallization fractionation treatment and additive addition treatment. The method greatly reduces the content of high-melting-point glyceride and wax in the natural ester insulating oil through the crystallization fractionation treatment, the pour point of the natural ester insulating oil can be reduced to -25 DEGC or below by effectively combining with additives, good physicochemical and electrical properties are kept, and the application requirements of the natural ester insulating oil in most regions of China can be met. The method has the obvious advantages of high applicability, simple process flow, low production cost, completeness in meeting the technical requirements of industrial production, andgood technical transformation and implementation prospects.