The invention discloses a preparation method of polyfuran dioctyl phthalate glycol ester. The preparation method comprises the following steps: (1) esterification or ester exchange reaction: adding furan dioctyl phthalate or furan dioctyl phthalate diester, ethylene and nitrogen-containing catalyst to a reactor, and reacting for 2-5 hours at 160-210 DEG C to obtain an esterification or ester exchange product; (2) polycondensation: reacting the esterification or ester exchange product in the conditions of pressure of less than or equal to 150Pa and temperature of 220-250 DEG C to prepare polyfuran dioctyl phthalate glycol ester. According to the invention, the efficient and high-selectivity nitrogen-containing catalyst is adopted, thus being favorable for improving the esterification or ester exchange rate, promoting polycondensation and improving molecular weight; and the prepared product is colorless or shallow in color, less in byproducts and good in structure regularity. According to the preparation method, only one nitrogen-containing catalyst is needed and is only added before reaction, adding of catalyst is not needed in the medium process, the process is very simple, the process is environmentally friendly, and realization of industrialization is facilitated.