TECHNOLOGY FOCUS - FOOD - Preferred Method: The method involves weighing the kudzuvine root, selecting raw materials, transferring the sorted raw material to washing device, separating waste and subjecting to starch dregs pre-process chamber. The method involves producing food and starch by transferring the washed kudzuvine root to drying and dehydrating device, weighing the kudzuvine root after dehydrating water from the kudzuvine root, subjecting to pulping centrifuge and second pulping centrifuge, respectively, obtaining the liquid after first and second pulping process, filtering the liquid, sterilizing the liquid, storing under vacuum conditions and using the liquid to produce healthcare food and other products, introducing the water which is separated by the starch depositing and separating device to the circulating water pool to supply water to the pulping centrifuge, conveying the thick liquid which is separated by the starch depositing and separating device to dry and wet marsh gas fermenting tank to ferment marsh gas, conveying the waste dregs which is separated by the starch depositing and separating device to starch dregs pre-process chamber to perform pre-fermentation, conveying the pre-fermented starch dregs to the dry marsh gas fermenting chamber to ferment marsh gas. The marsh gas fermented by the dry marsh gas fermenting chamber is subjected to a marsh desulfurizing and impurity-removing device and then the marsh gas is stored in a gas storage tank. The marsh gas is purified by purifying device, and the purified marsh gas is subjected to a marsh gas storage unit. The marsh gas fermented by the dry marsh fermenting chamber is subjected to the wet marsh gas fermenting tank to ferment marsh gas, where the heat energy for drying and dehydrating is supplied by steam furnace connecting tube and the marsh gas dregs of the dry marsh fermenting chamber are subjected to separator. The substances which cannot be separated are subjected to the dry marsh fermenting chamber again and the separated substances are subjected to ball mill. The processed products are subjected to the auxiliary materials regulating tank, and the mixture is subjected to organic fertilizer tabletting device after adding the auxiliary materials. The product is subjected to drying and dehydrating device and then the product is packaged by a packaging machine. The finished product is subjected to organic fertilizer storage unit provided with heat energy for drying and dehydrating the product. The dehydrated water is subjected to the furnace water injector through the connecting pump and the liquid after fermenting the marsh gas is subjected to fertilizer producing device. The finished product is subjected to storage tank and the marsh gas fermented by wet marsh gas fermenting tank is subjected to marsh gas desulfurizing and impurity-removing device. The redundant marsh gas liquid fermented by the wet marsh gas fermenting tank is subjected to the dry marsh gas fermenting tank through the conveying pump to ferment marsh gas. The marsh gas liquid generated by wet fermentation and dry fermentation can be regulated mutually. ACTIVITY - Fertilizer.