The invention relates to a preparation method of an aramid composite sound absorption material, comprising the following steps: punching dense micropores on meta-aramid fiber paper utilized as a substrate; carrying out plasma activation treatment by utilizing industrial gas; then, carrying out plasma grafting treatment on the activated meta-aramid fiber paper by utilizing polymer monomer; and finally, compounding the treated meta-aramid fiber paper with aramid felts. The sound absorption coefficient of the composite material is tested by a standing wave tube method. A result shows that the sound absorption property of the composite material is obviously improved; under the center frequency band above 1400Hz, the sound absorption coefficient of the composite material is more than 6 times of the sound absorption coefficient of pure aramid paper and is more than 2 times of the sound absorption coefficient of pure aramid felts.