The invention discloses a biological drying treatment device and method for domestic garbage. The biological drying treatment device comprises a biological drying chamber, a wastewater evaporation system, a condensation conversion system, an auxiliary system, an online exhaust gas and supply air monitoring system, an exhaust gas and supply air cyclic utilization system, and an automatic productionand distribution control system. According to the invention, wastewater evaporation and condensation conversion technologies of the invention can convert high-concentration percolate wastewater intolow-concentration condensed wastewater, so wastewater treatment difficulties and treatment cost are lowered; online monitoring and cyclic utilization technologies can reduce the supply volume of a fresh air source, decrease the amount of exhaust gas treated by an end exhaust gas treatment system and lower the cost of exhaust gas treatment; and an automatic distribution control system (DCS) can realize on-line monitoring of the parameters of a biological drying production process, centralized control of remote terminals and automatic execution of procedures, so the automation management level of a project is improved.