A plasma gasification device for converting raw garbage materials to synthetic gas with high heat value relates to a gasification process device of garbage. The device mainly comprises a gasification reaction furnace, a circular air pipe, a circular blower, a plasma burner, and a screw feeder, wherein the gasification reaction furnace is divided into a baking zone, a pyrolysis zone, a gasification zone, a burning zone and an air chamber according to operation conditions, a flue gas output port is arranged above the baking zone, a synthetic gas output port is arranged at the joint site of the pyrolysis zone and the gasification zone, and a flue gas recirculation input port is arranged inside the air chamber; and a flue gas recirculation air pipe is connected between the flue gas output port and an induced draft port of the circular blower, the air outgoing port of the circular blower is connected with the flue gas recirculation input port, a plasma spray gun is installed on the side wall of the burning zone, and the discharge port of the screw feeder protrudes from the front part of the baking zone into the furnace. The inventive device can treat garbage and convert the garage into synthetic gas with high heat value, which can be used for producing secondary clean energy products, at the same time.