The invention relates to a garbage drying combustion furnace, comprising a lower incineration chamber and an upper incineration chamber, wherein one side of the top of the lower incineration chamber is installed with feed breaking device; the feed breaking device comprises a feed barrel, a feed discharging barrel sleeved outside the feed barrel, a smashing cap installed on end of the feed discharge barrel and hot wind chamber installed outer wall of the feed discharge barrel, wherein annular material guiding space exists between the outer wall of the feed barrel and the inner wall of the feed discharge barrel, one end of the feed barrel is installed with a feed hopper and the other end has elastic gap with the the smashing cap. The feed barrel is installed with a spiral feed shaft, the spiral feed shaft is installed with a feed blade, one end of the spiral feed shaft goes the feed hopper and is connected with the driving shaft of the feed driving motor through a conveyor belt, and the other end of the spiral feed shaft is close to end face of the hopper. The side wall of the feed discharge barrel is provided with an air inlet connected with the hot wind chamber, and the air inlet is obliquely set towards feed discharge direction.