To reduce the cost of using sludge anaerobic fermentation products as carbon source and simplify the process, a novel method was proposed to study the feasibility of employing sludge fermentation products directly without separating fermentation broth and sludge or removing nitrogen and phosphorus. Different dosages of sludge alkaline fermentation products (i.e., 0,0, 0,0, and 200 mL, whose SCOD are 0,9, 8,6, and 792 mg) were poured into low C/N ratio municipal waste water to investigate nitrogen removal and phosphorus release. Results show that the nitric oxide (NO-_x-N) decreased first and then increased with the increase of the dosage of fermentation products. When the dosage was 50 mL with SCOD of 198 mg, nitrogen of 12.9 mg, and C/N ratio of 15.3, the concentration of NO-_x-N was the lowest, being only 1.2 mg/L and in the form of NO-₂-N, and the corresponding denitrification efficiency was 94.9%. However, with the increase of the addition of fermentation products, the amount of phosphorus release was not increased but decreased. When the dosage was 20 mL with SCOD of 79 mg, nitrogen of 5.2 mg, phosphorus of 1.6 mg, C/P ratio of 15.3, and C/N ratio of 49.5, the amount of phosphorus release was the highest at the end of the reaction, reaching 23.8 mg/L. Moreover, nitrification and denitrification processes showed that the bacteria activity was inhibited due to the damage of the cell structure of nitrifying bacteria and denitrifying bacteria in fermentation products, which was also proved by cell morphology. It indicated that the introduction of fermentation did not affect the stability of main microbial community structure in sewage nitrogen and phosphorus removal system. Therefore, it is feasible for sludge anaerobic fermentation products to be directly used as carbon source. In this study, the optimal amount for denitrifying nitrogen removal was 50 mL, and that for anaerobic phosphorus release was 20 mL.