In order to improve the capacitance of electrode materials, ferroferric oxide particles for making Fe3O4 electrode material were prepared by microemulsion method combining solvothermal method, and the effects of reaction temperature and calcination on the capacitance properties were studied. Results showed the capacitance of electrode materials prepared at 140 ℃ was much better than the ones prepared at 120 ℃ and 160 ℃. Calcination was proved to be beneficial for the capacitance performance of the ferroferric oxide electrode. The electrode obtained at the reaction temperature of 140 ℃ with subsequent calcination sustained better capacitance performances. When the current density was 1, 2, 5 A/g, the specific capacitance could reach 420.5, 230.0, 142.5 F/g, respectively.