Abstract: Disclosed is a method for synthesizing dihydroxyl-terminated polyphenylene oxide oligomer. The method for synthesizing dihydroxyl-terminated polyphenylene oxide oligomer, comprising oxidatively copolymerizing monohydric phenol and dihydric phenol in the presence of a metal-polyethyleneimine complex as a catalyst, to obtain the dihydroxyl-terminated polyphenylene oxide oligomer. The synthesizing method of the present disclosure uses a metal-polyethyleneimine complex as a catalyst, which has a milder catalytic activity, can effectively promote the reaction between the dihydric phenol and the monohydric phenol, increases the hydroxyl content of the product, meanwhile reduces the amount of the residual dihydric phenol monomer in the product, so that the quality of the product can be improved.