NOVELTY - A negative-pressure thermal distillation device comprises thermal distilling furnace, cyclone separator, cooler, liquid-separating tank, blower, sealed material-feeding silo and sealed material-discharging silo. The garbage slag obtained after burning of coal or thermal-distilling process is taken into furnace grating to burn and generates flue gas. The upper surface of thermal distilling furnace is equipped with flue gas outlet. The cyclone separator is connected to cooler, liquid-separating tank, another cyclone separator and blower.    USE - Negative-pressure thermal distillation device for domestic garbage.    ADVANTAGE - The device is environmental-friendly and effectively restrain the generation of dioxin.    DETAILED DESCRIPTION - A low-temperature negative-pressure thermal distillation device comprises thermal distilling furnace, cyclone separator, cooler, liquid-separating tank, blower, sealed material-feeding silo and sealed material-discharging silo. The thermal distilling furnace is divided into upper and lower furnaces. The lower furnace is combustion chamber which is equipped with sealed cavity and furnace grating whose bottom is connected to the blower. The garbage slags (carbon black) obtained after burning of coal or thermal-distilling process is taken into the furnace grating to burn and generate flue gas. The upper surface of thermal distilling furnace is equipped with flue gas outlet and the upper furnace is thermal distilling chamber which is connected with sealed material-feeding silo. The material-discharging silo hermetically forms the sealed transmission cavity. The thermal distilling chamber is outer surface of the upper surface of thermal distilling furnace and has smoke channel circumferentially connected to the combustion chamber. The upper surface of thermally distilled gas outlet is connected to the cyclone separator. The cyclone separator is connected to cooler, liquid-separating tank, another cyclone separator and blower. The combustion chamber burns to generate heat and flue gas which separately heats the thermal distilling chamber. Also claimed is low-temperature negative-pressure thermal distilling process. The sealed material-feeding silo, material-discharging silo send the leached, screened and dried garbage into the thermal distilling chamber. The blower is started and thermal distilling chamber internally generates the negative pressure which is insulated with the air to form the thermal distilling environment. The temperature of the thermal distilling chamber is at 300-350 degrees C. The garbage is decomposed into thermal distilled gas, garbage slag (carbon black) and waste liquid after being thermally distilled. The thermally distilled gas contains methane, ethane, ethylene, propane, propylene, iso-propylene, butane, 1-butane, iso-butene, pentane and carbon monoxide.