The invention discloses 12-(2-fluorophenyl)-benzo [h][1,3] methylenedioxy [4,5-b] acridine-10,11-diketone and a synthesis method thereof, and belongs to the technical field of dihydroketoacridine derivatives. The method comprises the steps of uniformly mixing 3,4-methylenedioxy aniline, 2-fluorobenzaldehyde, 2-hydroxyl-1,4-naphthaquinone, a catalyst and toluene sulfonic acid, performing heating and stirring, controlling the temperature to be 115-130 DEG C, and performing a reaction for 3-5h. Fluorine atom and methylenedioxy structures are introduced into 12-(2-fluorophenyl)-benzo [h][1,3] methylenedioxy [4,5-b] acridine-10,11-diketone, so that 12-(2-fluorophenyl)-benzo [h][1,3] methylenedioxy [4,5-b] acridine-10,11-diketone has higher activity, and more facilitates absorption. The synthesis method has the characteristics that the synthesis method is simple to operate, high in yield, green and environment-friendly, and raw materials are easy to obtain.