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Efficient deconstruction of lignocellulosic biomass by pretreatment is important for the production of fermentable sugars and biofuels. This study used butyric acid as a novel catalyst for corn stover pretreatment. The effects of butyric acid pretreatments on chemical composition and enzymatic digestibility were systematically investigated. The results indicate that a high linear correlation between xylan removal and fermentable sugars yield (r 2 = 0.91) was found. Pretreatment of corn stover with 50 g/L butyric acid at 180 °C for 0.5 h removed 83.17% of xylan and recovered 86.99% of glucan, and fermentable sugars yield of pretreated corn stover reached 97.16%. The physiochemical characterization results show that crystalline index (CrI) of corn stover was increased from 30.13% to 45.04%−48.38% after pretreatments, and the chemical structure and morphological features also exhibited positive changes for enhancing enzymatic hydrolysis. Meanwhile, the liquid fraction of pretreated slurry can be used for recycled pretreatment with 73.81% of fermentable sugars yield after four cycles. Additionally, the residual butyric acid was re-utilized as the co-substrate for Clostridium acetobutylicum ATCC 824 to produce biobutanol via acetone-butanol-ethanol (ABE) fermentation. The final production of butanol and solvents reached 8.38 g/L and 12.63 g/L under an optimized intermittent feeding strategy with a higher butanol/acetone ratio of 2.40 g/g. Overall, this work presents a novel pretreatment strategy to co-produce fermentable sugars and advanced biofuel from abundant lignocellulosic biomass. [Display omitted] • A novel butyric acid pretreatment method was developed for corn stover utilization. • The xylan removal has a positive effect on glucose and fermentable sugars yields. • Butyric acid pretreatment improved the glucose yield by 2.59-fold with cellulase. • Liquid fraction of pretreated slurry can be used for recycled biomass pretreatment. • Butanol titer was enhanced by 22.51% under intermittent feeding butyrate strategy. [ABSTRACT FROM AUTHOR]