To reuse biorefinery waste, cellulose ethanol lignin was treated with a laccase system and used as an adhesive for plywood panel preparation. The effects of the amount of laccase, the pH of the reaction system, the reaction temperature, and the reaction time on the bonding strength were studied. The reaction characteristics of the lignin were analyzed by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR). The results showed that the amount of laccase and the pH value of the reaction system had a significant effect on the bonding strength, and the addition of Tween-80 and polymeric diphenylmethane diisocyanate (PMDI) could improve the wet strength of the cemented system. FT-IR indicated that the lignin had been etherified and NMR analysis showed the partial ether bond in the β-O-4 structure was cleaved so that the lignin fragment was involved in the gluing of the small molecules. Microscopically speaking, the SEM analysis did not observe the activation of lignin adhesives infiltrating the wood substrate, indicating a weak mechanical gluing.