To explore the effects of microbial fermented feed on growth performance,nutrient digestibility and economic benefit of finishing pigs. A total of 240 healthy foreign Yuan hybrid pigs(average weight 19.38±0.51 kg)were randomly divided into 4 treatments with 6 replicates per treatment and 10 pigs per replicate. The experimental diets were supplemented with 0%,2%,4% and 8% fermented feed,respectively. The experiment lasted for 102 days. The results showed that:Compared with control group,the final weight of finishing pigs in 8% fermented feed group was significantly increased by 7.96%(P<0.05),the average daily gain was significantly increased by 9.75%(P<0.05),the average daily feed intake was significantly increased by 3.54%(P<0.05),and the ratio of feed to gain in control group was significantly decreased by 5.66%(P<0.05). DM digestibility of piglets in 4% and 8% fermented feed groups was significantly increased(P<0.05). The CF digestibility of piglets in 4% and 8% fermented feed groups was significantly increased(P<0.05),and the energy apparent digestibility in 9% fermented feed group was significantly increased(P<0.05). The total weight gain of finishing pigs in 4% and 8% fermented feed groups was increased by 3.83 and 7.98 kg(P<0.05),respectively,and the gross profit of each group was 412.86,412.50,431.84 and 480.02 yuan(P<0.05),respectively. Conclusion:8% fermented feed has the best growth promotion effect on finishing pigs.