The invention discloses a method and device for preparing
fertilizer from kitchen garbage. The method comprises crushing kitchen garbage, carrying out
solid-liquid separation, carrying out
pyrolysis carbonization on the separated
solid kitchen garbage to obtain
pyrolysis gas and carbon residue, washing the
pyrolysis gas, carrying out anaerobic
fermentation on the separated liquid to obtain a broth,
biogas residue and
biogas, carrying out aerobic
fermentation on the broth, then preparing organic-inorganic composite liquid
fertilizer from the obtained liquid, mixing the
biogas residue and the biogas residue obtained by the pyrolysis
carbonization, adding composite microbe
engineering bacteria into the mixture, and carrying out
solid state
fermentation to obtain the organic carbon solid
fertilizer. The method and device respectively carry out resourceful treatment on the solid kitchen garbage and the organic liquid, the organic liquid is treated by a
biotechnology so that the organic-inorganic composite liquid fertilizer is produced, and solid kitchen garbage is subjected to pyrolysis
carbonization so that energy and
biochar are produced.