Harmless production line for household garbage

The invention discloses a harmless production line for household garbage. The harmless production line comprises a first belt conveyer, a garbage smashing and cutting machine, a second belt conveyer, a metal sorting device, a garbage crusher, a negative pressure conveyer, a first settling tank, a first screw conveyer, a second settling tank, heating screw conveyers, a vibrating screen, a second screw conveyer and a granulating machine; the first belt conveyer conveys the household garbage to the garbage smashing and cutting machine, the cut household garbage falls on the second belt conveyer, the metal sorting device sorts out metal substances, and the metal substances are conveyed to the garbage crusher to be crushed, conveyed to the first settling tank and the second settling tank by the negative pressure conveyer, output to the heating screw conveyers to be disinfected and dried, then output to the vibrating screen and finally conveyed to the granulating machine by the second screw conveyer to be made into granular material. The household garbage can serve as raw material for production and can be recycled after being treated on the production line and made into granules.