Microbial genome editing based on homologous recombination uses its own Rec system to carry out homologous recombination of exogenous DNA to achieve allelic replacement of target genes, and recombination of genetic information between two homologous strands of DNA. By producing and isolating DNA fragments with genomic sequences similar to the part of the genome to be edited, these fragments are injected into monocytes. Once these fragments enter the cell, they can be recombined with the cell's DNA to replace the target part of the genome.