The invention relates to a high-specific-capacity MoS2/Mn2O3-nanometer-hollow-ball composite electrode material and a preparing method and application thereof. The preparing method includes the stepsthat a three-layer Mn2O3 hollow ball with the maximal specific capacity serves as a reactant; dispersion and exfoliation are carried out in an organic solvent with the mechanical exfoliation method toobtain single-layer MoS2; a strongly-basic solution is added into a mixed NMP solution of the single-layer MoS2 nanometer sheet and the three-layer Mn2O3 hollow ball to contend surface protons of thesingle-layer MoS2 nanometer sheet, and a single-layer MoS2/Mn2O3-nanometer-hollow-ball electrode is prepared. The high-specific-capacity MoS2/Mn2O3-nanometer-hollow-ball composite electrode materialand the preparing method and application thereof have the advantages that the single-layer MoS2 nanometer sheet is used in the composite electrode, and the composite electrode has the large specific area, and provides more active sites for a psedocapacitance reaction; through the advantages of the hollow structure of the three-layer Mn2O3 hollow ball, compared with a traditional electrode material, the composite electrode material has the super-high capacitive performance, and meanwhile the high-specific-capacity MoS2/Mn2O3-nanometer-hollow-ball composite electrode material is easy to prepare,convenient to store, long in cycle life and high in operability.