The invention relates to a genetically engineered bacterium for producing fucosyllactose and a production method of the genetically engineered bacterium, and belongs to metabolic engineering and food fermentation technologies. According to the invention, a synthetic biological means is utilized, an escherichia coli cell factory of fucosyllactose is constructed based on a de novo synthetic route, bypass related genes lacZ, wcaJ, nudD, pfkA and lon in host cells are knocked out by adopting a CRISPR / Cas9 gene editing technology, and genes manB, manC, gmd and wcaG are assembled through a multi-plasmid expression system, so that the fucosyllactose is obtained. Constructing expression vectors with different copy numbers to increase the expression level of key genes; fucosyltransferase from different sources is screened, so that the activity of rate-limiting enzyme is improved. The constructed recombinant escherichia coli can be used for synthesizing 2 '-fucosyllactose and 3-fucosyllactose by utilizing glycerol, is stable in heredity and high in expression level, and has obvious industrial production potential.