The invention relates to a genetically engineered bacterium for synthesizing N-acetylglucosamine and an application of the genetically engineered bacterium. The genetically engineered bacterium is recombinant corynebacterium glutamicum containing a glucosamine synthetase gene glmS and a glucosamine transacetylase gene gna1, and is modified by a chassis microorganism of which related genes of a GlcNAc reverse transport pathway, a catabolism pathway and a competitive metabolism pathway are knocked out; the genetically engineered bacterium also contains a 6p-GlcNAc specific phosphatase gene yqaBused for increasing the concentration of extracellular GlcNAc, and the genetically engineered bacterium expresses the glucosamine synthetase gene glmS, the glucosamine transacetylase gene gna1 and the6p-GlcNAc specific phosphatase gene yqaB. The genetically engineered bacterium is safe and non-toxic, can produce the GlcNAc at high yield by utilizing a microbial fermentation method, and is stablein batch, relatively low in production cost and wide in application prospect.