In order to obtain electrode materials with high specific capacity and good cycle stability, the solution co-precipitation method was used to prepare nano-manganese dioxide (MnO2) particles. On this basis, the influence of the dosage of polyvinylpyrrolidone dispersant on its capacitive performance was investigated. The results showed that the specific capacitance of the material reached the highest when the amount of polyvinylpyrrolidone was 2.0 g, and the specific capacitance of the material was 195.5, 180.5, 160.4, 142.7 and 121.4 F/g at the current density of 1, 2, 5, 10, 20 A/g, respectively. At 20 A/g current density, the specific capacitance retention was 62.1% compared with that of 1 A/g. During the long-time test of 1000 charge-discharge cycles, it showed excellent stability with the specific capacitance retention high up to 90.46%. Therefore, the prepared MnO2 was an energy storage material with good capacitive performance.