The invention discloses a recombinant bacterium utilizing glycerin to produce acrylic acid, a construction method and applications thereof, and belongs to the technical field of gene engineering. The provided recombinant bacterium is obtained through the overexpression of glycerol dehydratase gene, glycerol dehydratase reactivase gene, 3-hydroxyl propionyl coenzyme A dehydratase gene, and propyl aldehyde dehydrogenase gene. By using the recombinant bacterium, a metabolic route that can prepare acrylic acid from raw material namely glycerin through denovo synthesis is established. At the same time, the invention also provides a construction method and application method of the recombinant bacterium. According to the method, E. coli is taken as the host bacterium, acrylic acid is synthesized by taking glycerin as the substrate in the presence of escherichia coli for the first time, and a novel method is provided for acrylic acid production.