Immunosuppression is an important mechanism for the development of sepsis pathology, and is the key to the high mortality of sepsis. However, patients appear to be immunocompromised before sepsis onset due to lack of enough attention. Present sepsis models cannot fully mimic the onset of sepsis in patients. Hence, effective treatments in animal experiments could not be transformed into clinical application. In the present study, we improved the animal model of sepsis and used cyclosporine A immunosuppressive mice to make it closer to immune status before the onset of sepsis, followed by the intraperitoneal injection of Escherichia coli (E. coli) CMCC (B) 44,102 standard strain to produce the immunocompromised sepsis model. This trial systematically evaluates the new immunosuppressive sepsis model. Compared with routine sepsis models, the release of inflammatory factors in the new sepsis model was insufficient, blood bacteria were more cultured, diffuse intravascular coagulation (DIC) was more severe, lung, liver and kidney damage were heavier, and mortality rate was higher. In conclusion, the new sepsis model can mimic the patient's pre-onset immunocompromised state, is suitable for the development and evaluation of new methods of sepsis, and solves the controversy of sepsis treatment, providing new ideas and direction.