Abstract: using single factor completely random design and setting 4 treatments, i.e., control group (CK), adding 3% mushroom bran+0.1% cellulase (test groupI), adding 7% mushroom bran+0.1% cellulase (test groupⅡ) and adding 10% mushroom bran+0.1% cellulase (test group Ⅲ), the effects of different treatments on the productive performance of beef cattle were analyzed. The results showed that compared with the control group, the treatments of test groupⅡand test group Ⅲ significantly increased the daily gain level of beef cattle (P<0.05) and the contents of volatile fatty acids, acetic acid and butyric acid in rumen (P<0.05). And three treatments had no significant effect on the feed intake and pH value in rumen of beef cattle (P>0.05), and cellulase can improve the degradation rate of mushroom bran fiber. The results showed that applying suitable amount of mushroom bran to replace corn and adding a small amount of cellulase could significantly improve the productive performance of beef cattle.