There is increasing demand for the production of biofuels from lignocellulosic biomass. Lignocellulosic biomass consists mainly of three polymeric components: cellulose, hemicelluloses, and lignin. The separation of these components requires an effective pretreatment process to ensure high quality glucose production, and is highly influenced by several factors, including moisture content, cellulose crystallinity, lignin content, and available surface area. Over time, numerous pretreatment methods have been utilized to change the lignocellulosic fiber structure and to enhance the enzymatic saccharification of cellulose to polysaccharides. This article reviews thermal-based pretreatment of lignocellulosic fiber used for glucose production. Based on the reviewed studies, autohydrolysis of lignocellusic biomass, followed by the “Instant pressure drop (DIC),” method can be regarded as an effective pretreatment process of lignocellusic biomass.