Rice straw (RS) is one of the most abundant lignocellulosic biomasses in China, which contains mainly of cellulose, hemicellulose and lignin. In this study, a novel deep eutectic solvent (DES), foraceline, was prepared with choline chloride and double hydrogen bond donors (formic acid and acetic acid). By combining foraceline and sodium carbonate (1%), a two-stage pretreatment method was developed and applied in RS pretreatment to improve the biodegradability of lignocellulose. The highest glucose and total sugar of 37.3 g.L-1 and 42.8 g.L-1 were obtained after hydrolysis of 24 h using 50 FPU.g(totalsolid)(-1) of cellulase. The cellulase attached to RS was reutilized for five continuous cycles in which enzyme loading was reduced from 50 FPU.g(totalsolid)(-1) (Cycle I) to 30 FPU.g(totalsolid)(-1) (Cycle V), resulting in total sugar of 41.3-42.6 g.L-1 for each cycle. RS hydrolysates (Cycle I and V) was utilized in butanol fermentation by Clostridium saccharobutylicum DSM 13864, achieving butanol titer and yield of 9.5 g.L-1 and 0.25 g.g(totalsugar)(-1), similar to those of glucose medium. This study demonstrated the feasibility of this newly developed biomass pretreatment by dihydrogen bonding DES featuring cellulase recycling and high butanol yield.