System and method for preparing high-concentration biomass carbon source from kitchen waste

The invention discloses a system and method for preparing a high-concentration biomass carbon source by using kitchen waste. The method comprises the following steps: an extrusion cooking fat extraction hydrothermal treatment subsystem is separately provided with a kitchen waste inlet, a slurry outlet and at least one steam inlet, and the slurry outlet is connected with a biodegradation device; a biological hydrolysis device is provided with a fermentation liquid outlet and a fermentation residue outlet separately, the fermentation liquid outlet is connected with a filtering and purifying device, and the fermentation residue outlet is connected with an anaerobic fermentation device; a biogas outlet of the anaerobic fermentation device is connected with a fuel gas heating device; the fuel gas heating device is provided with at least one steam output port, and the steam output port is connected with the steam inlet of the extrusion cooking fat extraction hydrothermal treatment subsystem; and the filtering and p