TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The device further comprises a cyclone separator, connected with the pyrolysis tank and a dust catcher, connected with the purification separation device. The tri-state purification separation device comprises a separator and a condenser. The gas purification device comprises a first chamber, a second chamber and a separator between the first and the second chambers. The gas purification device is filled with neutral water or calcium hydroxide liquid. The lower end surface of the separator is placed 15-20 cm below the liquid level. The first chamber is provided with a spraying port for spraying neutral water or calcium hydroxide liquid and is connected with the first chamber and an air pipe of the second chamber. The air pipe is located in the second chamber 5-10 cm below the neutral water or calcium hydroxide liquid level. The outer side surface of the second chamber of the gas purification device is provided with a circulating pump to control the spray circulation of liquid. The pneumatic device is a Roots blower, an induced draft fan or a vacuum pump. The device comprises a reflux pipeline provided with an adjusting valve, arranged between the tri-state purification separation device and gas purification device connecting pipeline and used for controlling the guiding amount of air or oxygen into the pyrolysis tank. The static separation device comprises a static separator, an acid tank, and a tar tank. The thickness of the pile stalk prior to burning is 20 cm or one quarter of the tank depth. The suction flow rate of the pneumatic device is 1000-3000 m3/hour or 400-1200 m3/hour. The reflux pipeline of the pneumatic device is provided with an adjusting valve to control the suction flow rate. Preferred Method: The straw is added after the complete combustion of the straw pile to obtain a thickness of 20 cm or one quarter of the tank depth. The straw is added at a uniform rate of 0.5 -1.5 ton/ hour. The processing of uncondensed gas in the gas purification device comprises leaching and washing.