Effective pretreatment of wood pulp waste is important for enhancing enzymatic saccharification. For this reason, wet oxidation process conditions were considered with the hypothesis that the alkaline oxygen conditions would favor delignification and hydrolysis of lignocellulose. Enzymatic saccharification was greatly improved to 42.9% in terms of reducing sugar yield under the conditions of pH = 10, oxygen pressure = 1.2 MPa, time = 15 min, and temperature = 195 °C. A total of 39% of lignin and 73% of hemicellulose were removed and dissolved into the hydrolyzate. Furthermore, the chemical structure, crystallinity, and morphology of the treated substrate were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM).