Large-sized metal oxide particles have the potential to constitute cheap, high-performance, and high-stability supercapacitor electrode materials. Herein, the marketable large-sized Co3O4 particles (~6 [my]m) as the starting raw material, inexpensive Co3O4/MoS2 core-shell heterogeneous composites have been one-step fabricated via an improvised MPCVD system modified by a domestic microwave oven. After that, the surface morphology, composition structure, and valence state of elements were analyzed to the confirmed successful synthesis of MoS2 on the surface of Co3O4. Besides, the performance was tested by cyclic voltammetry and galvanostatic charge-discharge method. The results show that the synergistic effect of Co3O4 core and MoS2 shell can effectively improve the material's electrochemical performance. The specific capacitance of Co3O4/MoS2 composite can reach 337 F g-1 with a current density of 0.5 A g-1, which is six times more than the raw Co3O4 powder. Furthermore, it could maintain 93.6% of the initial specific capacitance after 2000 charges and discharges. Finally, the mechanism of material performance improvement is proposed.