The invention relates to a composite electrode material, a manufacturing method and application thereof. The composite electrode material comprises manganese oxide, graphene and graphite oxide. The manufacturing method includes the following steps, first step: adequately milling graphene then ultrasonic dispersing it into water; second step: dissolving hypermanganate into the water containing graphene and obtaining the aqueous solution containing permanganate ion and graphene; third step: adding polyethylene glycol into the aqueous solution of second step under stirring and obtaining mixed solution; fourth step: stirring the mixed solution until fuchsia completely faded, then filtering, washing and drying precipitate and obtaining the composite electrode material. The composite electrode material has the following advantages: high specific surface area, high conductivity and high specific capacity, and can be applied to supercapacitor electrode material.