The invention provides a vector strain of a recombinant single-chain antibody expressing DNase I, AIF or integrating toxins, and an application of the strain. The technical scheme depends on a single-chain antibody for specifically identifying a TEM1 protein; and an effect of specifically killing tumors is achieved by carrying humanized toxins DNase I and Aif in combination with tumor internal specific aggregation and intracellular invasion characteristics of attenuated salmonella typhimurium VNP20009. Specifically, recombinant plasmids Abvec-Igk-DNase I, Abvec-Igk-T18-Dnase I, Abvec-Igk-Aif and Abvec-Igk-T18-Aif are constructed firstly; the recombinant plasmids are amplified and introduced into a salmonella typhimurium VNP20009 strain in an electric shock transformation way; based on the intracellular invasion characteristic of the attenuated salmonella typhimurium, the protein expression is realized by taking HEK293-T cells as a host; and finally, the attenuated salmonella typhimurium inside and outside cells is killed by a serum culture medium containing penicillin and streptomycin, the recombinant plasmids are released to eukaryocytes, and supernate containing a target protein is obtained after cell disruption.