ABSTRACT Lignin dissolution and the fluid behaviour of reaction systems play important roles in the conversion rate of lignin. This study investigated the solubility of enzymatic hydrolysis lignin (EHL) in 1-butyl-3-methylimidazole bisulphate ethanol solutions ([BMIM]HSO4/ethanol) and the dynamic shear rheological characterisation of EHL-[BMIM]HSO4/ethanol. Different with [BMIM]HSO4/water, [BMIM]HSO4/ethanol exhibited excellent abilities to dissolve EHL at [BMIM]HSO4% 20%–90%, with the maximum EHL solubility obtained at 40%–70%. The dynamic shear rheological characterisation strongly depended on temperatures, [BMIM]HSO4% and EHL%, exhibited as pseudoplastic fluid at higher [BMIM]HSO4% and EHL%, and Dilatant fluid at lower [BMIM]HSO4% and EHL%. Adjusting an appropriate [BMIM]HSO4% and EHL%, EHL-[BMIM]HSO4/ethanol was Newtonian fluid with the viscosity stable. EHL was regenerated from EHL-[BMIM]HSO4/ethanol without obvious changes in the chemical structure and thermal behaviour. This study provided ideas for the design of the [BMIM]HSO4/ethanol system and the optimisation of conversion processes for the economic utilisation of lignin.