In order to establish an efficient process for the pretreatment of lignocellulosic biomass to deconstruct the complex structure and improve enzymatic hydrolysis efficiency of polysaccharide fractions, choline chloride(ChCl) and glycerol(Gly) were used to synthesize green deep eutectic solvent(DES) for corn stover pretreatment.The deconstruction effects of DES on corn stover under different synthesis conditions were compared, and the chemical reagents were added to enhance pretreatment. The results indicate that, pretreatment at 120 ℃ for 3 h by DES (at a molar ratio of 1∶2) with 1% H₂SO₄ addition improves the glucan content from 334% to 512%. In this case, the removal rates of xylan and lignin reache up to 867% and 390%, respectively. After 72 h enzymatic hydrolysis by cellulase, the productions of glucose and fermentable sugars are relatively high, reaching 290 g and 307 g from 100 g of corn stover. Therefore, the H₂SO₄-assisted DES system efficiently remove xylan and lignin, which facilitates the improvements of hydrolysis and fermentable sugars production. This study develops a green and high-efficient pretreatment to provide fundamental data and technical support for valorization of renewable and abundant agricultural residues in China.