The invention provides a synthesis method, a derivative and a battery system of an anthraquinone derivative containing a carboxyl group. The synthesis method of the anthraquinone derivative containingthe carboxyl group includes the following steps that S1, dibasic acid containing a terminal carboxyl group and sulfoxide chloride are mixed, toluene is added as a reaction solvent, a catalyst is added, and heated to a set temperature reaction; S2, after the reaction is completed, the solvent and the sulfoxide chloride are removed, the toluene is added for distillation, and a reactant is obtained;S3, the reactant is mixed with amino-anthraquinone, the toluene is added as the reaction solvent, and heating is conducted to a reflux reaction; and S4, after the reaction is completed, the solvent is removed, solids are filtered and removed, the pH value of a filtrate is adjusted to a predetermined value, the solids are separated out, filtered, washed and dried, and the anthraquinone derivativecontaining the carboxyl group is obtained. According to the synthesis method of the anthraquinone derivative containing the carboxyl group, simpleness is achieved, operation is easy, the cost is low,and the synthesis method can be applied to the battery system to solve the problem of electrochemical energy storage.