The invention discloses a fermentation process for producing L-tryptophan through recombinant escherichia coli. The fermentation process comprises the following steps that activated recombinant escherichia coli stains are subjected to seed culture to obtain a seed solution, the seed solution is inoculated into a fermentation tank loaded with an initial fermentation medium for fermentation culture,wherein in the fermentation culture process, ammonium acetate and corn slurry are added into the fermentation tank in an intermittent flow mode. In the fermentation process, by adopting a nitrogen source intermittent addition mode with combination of the corn steep liquor and the ammonium acetate, the yield of fermented tryptophan is increased by 35%, and the yield of a fermented product, namelythe L-tryptophan, is increased.