The objective of this trial was to investigate the potential benefits of enzyme and probiotic supplementation on the growth performance, nutrient digestibility, carcass traits, and meat quality of Simmental cattle. Sixty Simmental steers (367.75±4.69 kg) were randomly divided into three groups: control (fed basal diet), BC1 group (fed basal diet and 10 g/d brewer's yeast and cellulase supplementation per cattle), and BC2 group (fed basal diet and 20 g/d brewer's yeast and cellulase supplementation per cattle). A 10-d preparation period was followed by a 120-d experimental period. The results showed that the final weight of the BC2 group was greater than that of the control group. Also, feed conversion ratio of the BC2 group was better than that of the control group. Net meat weight increased by 3.86% in the BC2 group compared with the control group. The apparent digestibility of neutral detergent fiber, acid detergent fiber, and crude protein of the BC2 group was greater than that of the control group. Dietary supplementation with brewer's yeast and cellulase supplementation could improve the growth performance and nutrient digestibility of Simmental cattle.