Abstract: Using Trichoderma harzianum for producing cellulose enzyme to degrade straw was advantageous to returning straw to field and reducing the waste biomass. Trichoderma was extracted continuously. Straw degradation rate was used as indicators to research straw degradation ability. With straw weightlessness rate, and changes in the N, P, K content in the straw as indexes, through multiple extractions, the ability of straw degradation was improved. To the fourth extraction, effect of trichoderma viride on straw degradation rate was the highest, to the fifth extraction, straw degradation rate fell slightly, and to the sixth extraction, the decline was most obvious. Multiple extractions could improve the ability of trichoderma in straw degradation, but not the more the better, with four times as advisable.