The invention discloses a garbage drying and pyrolyzing method. The method comprises the following steps that pyrolytic garbage is poured into a feeding hopper, the garbage enters an extrusion cylinder, a driving motor is started to drive an extrusion rotating shaft to rotate, the garbage moves rightwards under the action of a spiral blade, the garbage is extruded through the inner wall of the extrusion cylinder to discharge water, sewage drips into a sewage tank and is discharged from a sewage outlet, and the garbage enters a crushing box from a first discharging opening; a crushing motor isstarted to drive a first crushing shaft and a second crushing shaft to rotate, crushing blades on the crushing shafts crush the garbage, and the crushed garbage enters a drying box; and a first heating plate, a second heating plate and a fan are started to dry the garbage in the drying box, generated gas enters a dust removal water tank from an exhaust pipe, an electric valve at the bottom of thedrying box is opened, and the dried garbage is discharged into a pyrolyzing furnace. According to the method, the moisture content in the garbage is greatly reduced, the pyrolysis speed of the garbagein the pyrolyzing furnace is increased, residues are reduced, and generated gas does not contain a large amount of incineration particles.