The invention relates to a plasma garbage gasification device and process. The device comprises a gasification reaction chamber, a steam heat exchanger, a steam buffer tank, an air buffer tank, an inner and outer double-cyclone heat exchanging dust collector, a cooling tower, a hydrogen sulfide removal sprayer, a water ring compressor, a gas-water separator, a gas storage tank and a control system of the device, which are connected through a gas pipeline; the gasification reaction chamber comprises an automatic feeding device, an automatic ignition device, a primary gasification zone and a plasma reaction zone; and the plasma reaction zone consists of a secondary refining zone and a gas refining zone. The process comprises the following steps of: gas generation; gasification medium preheating; gas purifying and filtering; and gas compression and storage. The invention has the characteristics of simple structural design, reasonable energy efficiency utilization, low primary input cost and low power consumption, and particularly, harmful substances such as dioxin and the like generated in the gasification process can be effectively removed, the volume reduction ratio is increased, and the waste is turned into the wealth.