The invention provides construction and usage of lactobacillus single-plasmid Nisin inducible expression vector, which belongs to the field of biotechnology. The construction comprises: a, acquisition and identification, the preparation of chromosome DNA producing Nisin lactococcus lactis, the design and synthesis of primer, the PCR amplification, recovery, pGEM-T connection and transformation ofa nisRK gene, and the identification of the nisRK gene; and b, the construction of pW425N, the recovery, connection and identification of the nisRK gene and a basic vector pW425et, the acquisition and identification of inducible promoter nisA gene, and the construction of pW425N. The usage comprises: a, the acquisition and identification of a green fluorescent protein gfp gene; b, the construction and identification of a recombinant expression vector; c, the determination of the inducible expression function of a Nisin inducible expression vector for green fluorescent protein; and d, the detection of lactobacillus stability. The invention has the advantages of avoiding the troublesome operation of integrating chromosomes of host bacteria in the prior system and simplifying the construction of recombinant genetic-engineering lactic acid bacteria.