The invention relates to the fields of a novel chemical electric power source and a new energy material, and particularly discloses a graphene/molybdenum disulfide composite electrode material and a preparation method of the composite electrode material. The preparation method comprises the steps of: (1) preparing graphite oxide from graphite as a raw material by an oxidation and intercalation method; (2) dissolving prepared graphite oxide with deionized water, carrying out ultrasonic stripping to obtain a graphene oxide solution, then adding DMF (dimethyl formamide) and molybdate, finally adding a reducing agent, and dispersing uniformly to obtain a mixed solution; and (3) transferring the mixed solution to a reaction kettle, keeping the temperature in the temperature condition of greater than or equal to 180 DEG C for 5-10h, centrifuging and washing the product to remove DMF, and drying to obtain the graphene/molybdenum disulfide composite electrode material product. The preparation method of the graphene/molybdenum disulfide composite electrode material is simple, uniform in reaction system and low in production cost, and is particularly suitable for requirements of industrial large scale production; and the prepared product graphene/molybdenum disulfide composite electrode material has better electrochemical performances.