Lignocellulosic biomass is undissolvable in water and conventional solvents for its complex natural recalcitrance, which significantly hinders its efficient utilization. Herein, we provided an efficient process for the dissolution of corn straw under mild conditions with the solution of ethanol, H₂SO₄, H₂O₂ and H₂O. The research emphasis is the effect of temperature on the dissolution process. Results showed that the components of cellulose, hemicellulose and lignin can be separated from the corn straw by adjusting the dissolution temperature. Part of the dissolved cellulose and hemicellulose were further converted into sugars and chemicals (such as furfural, 5-hydroymethylfurfural, ethyl levulinate, levulinic acid) during the dissolution process. Released lignin was destroyed into fragments and was recovered as organosolv lignin with lower molecular weight. Furthermore, residues and the recovered lignin obtained at different dissolution temperature were characterized carefully by FTIR, NMR, GPC and elemental analysis and the dissolution mechanism was discussed.