The invention belongs to the field of chemical industry, and particularly relates to an activated carbon supported metal complex and an application of the metal complex serving as a catalyst to preparation of dimethyl disulfide. A preparation method of the activated carbon supported CoL (Cl2) (CoL) metal complex includes the step: supporting the CoL (Cl2) (CoL) metal complex on modified activated carbon by a chemical grafting method to obtain the activated carbon supported CoL (Cl2) (CoL) metal complex. The modified activated carbon is 1,5-dibromopentane modified activated carbon. The catalyst is stable in structure and reusable, can have alkali resistance, pressure resistance and high-temperature resistance in a reaction system and effectively catalyzes and oxidizes methyl mercaptan salt to prepare the dimethyl disulfide. The catalyst and products can be effectively separated in the preparation process of the dimethyl disulfide, the purity of obtained products catalyzed by the catalyst is higher than that of obtained products catalyzed by a free CoL (Cl2) (CoL) metal complex. The yield of the obtain DMDS (dimethyl disulfide) can reach 76.7%, and the purity of the product can reach 100%.