The invention relates to the field of wastewater treatment and especially relates to a system and a method of pretreatment of household garbage pyrolysis condensation wastewater. The treatment system includes: a circulating adsorption oxidizing column having a water inlet, a first water outlet, a second water outlet, a water distribution packing layer, and a pyrolysis charcoal packing layer; an oil separation and precipitation system; a transporting apparatus used for transporting the pyrolysis condensation wastewater to the circulating adsorption oxidizing column; an oxidant addition system for adding an oxidant; a pH regulation section for regulating pH value; an ammonia stripping tower for performing blow-stripping treatment. The system and the method fully consider the characters that the pyrolysis condensation wastewater is acidic and is high in temperature, wherein the pyrolysis condensation wastewater is treated by means of pyrolysis charcoal, thereby achieving wastewater treatment by waste solid. In addition, saturated pyrolysis charcoal is fed back to the furnace for circulating pyrolysis, thereby being free of secondary pollution, not increasing the total soluble solid content in the wastewater and not generating sludge. The system and the method are low in cost and are easy to control, and have good effect of increasing biodegradability.