Cellulosic ethanol has attracted a lot of attention because of its great benefits for social and environmental sustainability. The adverse properties of lignocellulosic biomass (ie low bulk density, fluffy / difficult to handle and easily contaminated by microbes) and problems related to biomass pretreatment (ie high energy consumption, difficulties with scale-up and low fermentability of pretreated biomass) largely impede the commercialization of cellulosic ethanol. To address these issues, we invented a novel pretreatment method that investigated the compaction of lignocellulosic biomass with alkaline chemicals (DLC) and DLC onto corn stover (CS). DLC-CS has a high density and longevity, preventing contamination and completely preserving the sugar, which makes biomass logistics much easier. DLC-CS showed a high enzymatic digestibility and a high fermentability after storage. DLC-CS containing calcium hydroxide gave 21.4 g of ethanol per 100 g of CS, which was further improved to 25.3 g of ethanol per 100 g of CS using a regular steam autoclave. An ethanol titer of 70.6 g L.-1 was achieved for the first time without washing or detoxifying the pretreated biomass. These promising results demonstrated the great potential of DLC pretreatment for the production of lignocellulosic biofuels.