The invention relates to the technical field of biology, in particular to application of a small molecular compound to improvement of the pathogenic bacteria clearing capacity of a host and application of the small molecular compound to preparation of pathogenic bacteria infection resistant drugs. According to the invention, a metabonomics technology is utilized, and metabolic changes of the serumof mice infected with pathogenic bacteria are analyzed, so that a small molecular compound capable of improving the pathogenic bacteria clearing capability and resistance capability of a host, reducing the content of pathogenic bacteria in the host, improving the survival rate and particularly improving the staphylococcus aureus / MRSA infection resistance capability of the host can be screened out. Directed at the application of the small molecule compound, and the effect of the small molecule compound is realized by taking metabolism to adjust the immunity of the host as an entry point for adjusting the immunity of a host to resist pathogenic bacteria infection, so that the risk of generating drug-resistant bacteria can be eliminated by the method. Besides, the small molecular compound can play a better role in protecting the host in the synergistic effect of antibiotics, is beneficial to shortening the service cycle of the antibiotics, and reduces the generation of drug-resistant bacteria as much as possible.