The invention relates to a method for realizing nitrogen source recycling utilization by utilizing waste cell microbial fermentation, comprising: (1) waste cells are pretreated; (2) cell hydrolysate is prepared; (3) a microbial fermentation culture medium is prepared by using the cell hydrolysate as a nitrogen source for carrying out fermentation production. in the invention, the cell hydrolysateprepared by utilizing fermentation waste cells is used as the nitrogen source to carry out the microbial fermentation production, the using amount of yeast powder, peptone and expense nitrogen sourcecan be reduced, and the recycling utilization of the nitrogen source can be realized in the fermentation process, the production cost is not only reduced, but also the waste treatment burden is alleviated, thereby achieving the green, environmental protection and energy-saving social benefits; the technical proposal is effective and feasible.