Disclosed is a preparation method of an electrode modifying material of a thin-film battery. The preparation method comprises the steps of 1, preparing a first mixed solution with 3 mg of methyl trioctyl ammonium chloride, 10 ml of sodium carbonate aqueous solution with the concentration of 2 mol/L and 6 ml of toluene; 2, adding 5 mg of first monomers into the first mixed solution prepared in thestep 1; 3, preparing a second mixed solution with 5 mg of tetrakis(triphenylphosphine)palladium, 10 ml of sodium carbonate aqueous solution with the concentration of 2 mol/L and 6 ml of toluene; 4, adding 8 mg of second monomers into the second mixed solution prepared in the step 3; 5, mixing the solutions obtained in the step 2 and the step 4 evenly, and conducting precipitation for 10 hours; 6,repeatedly conducting vacuumization and introducing nitrogen three times, and conducting oil bath heating at 89 DEG C for 70 hours.