[Objective] The aim of the study was to discuss the optimum extraction technology and reaction condition of cellulase.[Method] With Trichaderma reesei Rut C-30 as fermentation strain,it was cultured at 30 ℃ and rotation speed of 170 r/min for 8 d to produce cellulase by fermentation.The crude enzyme solution was purified by salting-out technology.The technological condition of extracting cellulase was discussed through orthogonal experiment.And with the activity of CMC-Na as index,the optimum reaction condi...