Fermented corn stalk (FCS) was used to replace the basic diets and the effects of dietary nutrient levels on the growth performance, nutrient digestibility, slaughter performance, meat quality, and economic benefits of different growth stages of Songliao black swine were studied to determine the appropriate level of substitution for fermented corn stalk. A total of 96 healthy Songliao black pigs with an average body weight of (60.52±4.59) kg were randomly divided into 4 groups with 3 replicates in each group and 8 pigs per replicate. The test was divided into two fattening stages: fattening stage 1 (60-90 kg) and fattening stage 2 (90-120 kg). Group 1 represents the control group and pigs in this group were fed the basal diet. Group 2, Group 3 and Group 4 were the trial groups and pigs in these groups were fed with 6%, 12% and 18% fermented corn stalk, respectively. The experimental period lasted for 80 days (40 days +40 days). At the end of the experiment, the growth performance, slaughter performance, nutrient digestibility, and meat quality of Songliao black swine were tested. The results showed as follows: The final body weight and average daily weight gain of group 2 were significantly higher than those of group 4 (P<0.05). In addition, the feed conversation ratio of group 1 and group 2 was significantly lower (P<0.05) than group 3 and group 4. The digestibility of crude protein and crude fat in group 2 increased by 2.27% and 1.33% compared with group 1. The digestibility of crude fiber in group 1 and group 2 was significantly higher (P<0.05) than that in group 3 and group 4. The digestibility of neutral detergent fiber in group 1 was significantly higher than group 4 (P<0.05). The difference in the slaughter rate was not significant (P>0.05) in each group and the back fat thickness decreased with the increase of FCS addition. The loss of drip in 24 hours was lower in group 2, which was significantly lower than that in group 3 (P<0.05). The rate of cooked meat in group 1 was not significantly different from that in group 2. Calculation and analysis of economic benefits show that the feed cost of all the groups increased with the increase of FCS addition, but the economic benefits of group 2 was the highest. The economic benefits of each pig in group 2 was higher than group 1 by 14.17 yuan. In summary: the use of 6% FCS to replace the basic diet may adjust the nutritional levels of the diet, and hence improve the growth performance, economic benefits, feed nutrient digestibility, and meat quality of Songliao black swine. 