NOVELTY - The device comprises a fermentation bin containing bio gas, a hydrolyzing and fermenting chamber, a feeding bin, a spiral pump, a heat exchanger for heating the feed steam, a material discharging and regulating chamber, and main spiral wings having a spiral structure and provided with a sheet. The spiral pump, the heat exchanger, the fermentation bin and the hydrolyzing and fermenting chamber are fixed with a cylindrical cabin body. The sheet covers the cylindrical cabin body. The spiral structure is parallelly or vertically arranged with the main spiral wings.    USE - The device is useful for dry fermenting biogas (claimed).    ADVANTAGE - The device ensures continuous dry fermentation of the biogas.    DETAILED DESCRIPTION - The device comprises a fermentation bin containing bio gas, a hydrolyzing and fermenting chamber, a feeding bin, a spiral pump, a heat exchanger for heating the feed steam, a feed steam discharging and regulating chamber, and main spiral wings having a spiral structure and provided with a sheet. The spiral pump, the heat exchanger, the fermentation bin and the hydrolyzing and fermenting chamber are fixed with a cylindrical cabin body. The sheet covers the cylindrical cabin body. The spiral structure is parallelly or vertically arranged with the main spiral wings. The main spiral wings are connected with a top end and a bottom end of the cylindrical cabin body. The cylindrical cabin body includes a slot, a main spiral vane, and a spiral fin fixing column. A transverse fin is arranged on the main spiral wing. A transverse spiral wing is provided with the main spiral wing. The main spiral wings are parallely arranged on a circular pole and connected with each other. A gap between the main spiral wings and the circular pole is 5-10 mm. A middle portion of the cylindrical cabin body is provided with transverse fins. An upper surface of the main spiral wing is acquired to a transverse multi-vane. A bottom surface of the cylindrical cabin body is provided with a seal disk. The seal disk is set with a feeding port and a discharging tube. An inner stirrer is set with a stir device. A regulating chamber is connected with the spiral pump. The heat exchanger is set with a feeding tube of the heat exchanger. A driving gear of the hydrolyzing and fermenting chamber is connected with the seal disk. The discharge tube is set with the hydrolyzing and fermenting chamber. An outer surface of the hydrolyzing and fermenting chamber is connected with the driving gear for rotating the hydrolyzing and fermenting chamber. The hydrolyzing and fermenting chamber and the fermentation bin are arranged with each other along a center axis at an angle of horizontal line of 5-30 degrees . An INDEPENDENT CLAIM is included for a method for dry fermenting biogas.