The invention discloses a preparation method of a polyacrylonitrile/molybdenum disulfide composite material applied to a super capacitor. Sodium molybdate dihydrate (Na2MoO4.2H2O), thiourea (CH4N2S) and a polymethyl methacrylate/polyacrylonitrile (PMMA/PAN) core-shell structure are uniformly mixed. Hydrothermal reaction and high temperature carbonization are carried out to acquire the MoS2/PAN composite material. According to the invention, the preparation method uses PMMA as a template to form a PAN hollow spherical structure with uniform macropores; MoS2 nanoflowers grow on the surface of PAN; the composite material facilitates the transport of electrolyte ions, has the advantage of high specific surface area, and is favorable for the formation of a double-electrode layer; and the entirepreparation process is simple and environment-friendly.