A method for degrading corn straws is characterized by comprising the following steps: specifically mechanically crushing, sieving and
drying the corn straws, then degrading
lignin in the corn strawsby using immobilized
laccase taking Cu2+ modified Fe3O4-NH2-PEI
magnetic nanoparticles as carriers, recovering the immobilized
laccase, boiling the degraded corn straws, then adding NaOH for washing,and adding
cellulase for further degrading the
cellulose. According to the method, the affinity between the immobilized
laccase and a substrate is enhanced, the stability and the activity of the laccase in an application process are improved, thus, the degradation efficiency is improved, and the degradation rate of the
lignin reaches 40.76% or above. Inhibition of the immobilized laccase and degradation products such as phenolic substances generated by degradation on the
cellulase activity is eliminated, so that the
cellulase activity is guaranteed, and the conversion rate of the
cellulose isimproved, and reaches 46.85%.