The invention discloses a ferricyanide composite electrode material preparation method and applications of the ferricyanide composite electrode material in detection of hydrogen peroxide, and relatesto preparation and applications of a nanometer electrochemical material. The preparation method comprises: mixing K3Fe(CN)6, a AgNO3 solution and a LiCl solution to obtain a Li3Fe(CN)6 precursor; andplacing an aniline monomer, the prepared Li3Fe(CN)6 precursor and treated grapheneized carbon nano-tubes in a hydrothermal kettle, carrying out a reaction, filtering, and drying to obtain the LiPB-Pan-PUCNTs composite material. According to the present invention, Li3Fe(CN)6 has the oxidation-reduction potential in the electric conduction potential range of PAn, such that the PAn array can rapidlytransfer the charge to the oxidation-reduction center of Li3Fe(CN)6; and the grapheneized carbon nano-tubes have advantages of excellent conductivity, large specific surface area and biocompatibility,such that the in-situ polymerization and mixing can improve the conductivity and the dispersibility of the composite material and can rapidly achieve the direct electron transfer to the electrode surface so as to correspondingly improve the response sensitivity to the hydrogen peroxide detection.