Abstract: Larch,corn straw,air-dried cow manure and dry oil sludge were selected as the representative raw materials to investigate the gasification process in a fixed bed microwave reactor. The gas release process of larch and corn straw is mainly concentrated in the heating process while the gas contribution in the constant temperature process is small. Larch and corn straw are ideal raw materials for microwave gasification due to their higher gasification efficiency,gas yields and effective conversion of carbon. The low gasification efficiency and slow heating rate of air-dried cow manure with microwave heating is put down to its low volatile content and high ash content. The oil sludge can be heated rapidly with microwave heating,but its gas release process is mainly concentrated in the constant temperature stage. The particularity of microwave heating is beneficial to improve the recovery of light oil in oil sludge.