The invention discloses a method for synthesizing benzo[c]pyridine[4,3,2-mn]acridine-8-one. The method comprises the following steps of: performing intramolecular tandem cyclization reaction on 2-[3-(2-amidophenyl)-2-propynylamino]quinone with a 1,5-eneyne structure under the action of a metal catalyst, and purifying to obtain the benzo[c]pyridine[4,3,2-mn]acridine-8-one, wherein R refers to hydroxyl or methoxy; R1 and R2 refer to halogen atoms or alkyl with 1 to 6 carbon atoms; the intramolecular tandem cyclization reaction is homogeneous metal catalysis reaction, and the metal catalyst is gold salt or univalent gold coordination complex; the using amount of the catalyst is equivalent to 0.01 to 0.5 of the quinone raw material; and after the intramolecular tandem cyclization reaction is finished, purification, namely quick column chromatography, is carried out and the benzo[c]pyridine[4,3,2-mn]acridine-8-one is obtained. The raw material is simple and readily available, the reaction conditions are mild, and the chemical regioselectivity is high.