Sepsis is a life-threatening condition associated with high mortality rates in clinical settings. The subsequent immunosuppressive state is strongly correlated with adverse patient outcomes. Establishing robust animal models is therefore essential for elucidating the pathophysiological mechanisms of sepsis-induced immunosuppression and developing therapeutic interventions. Current models, however, are predominantly employed in sepsis hyperinflammation studies, while their utilization specifically for the immunosuppression phase remains limited. In addition, standardized assessment criteria for immunosuppression are lacking across different investigations.Commonly employed models include cecal ligation and puncture ( CLP ) and lipopolysaccharide ( LPS ) administration. Although cecal ligation and puncture effectively recapitulates the clinical pathology, it suffers from significant outcome variability. Conversely, although lipopolysaccharide administration is technically straightforward,its artificial nature fails to replicate the polymicrobial pathogenesis of natural infection. Quantitative analysis of immune cell populations, cytokine profiles, and immune organ status provides a reliable assessment of immunosuppression severity in animal models. By synthesizing recent literature, this review consolidates the method ologies and assessment parameters for establishing immunosuppressive sepsis models. By critically evaluating the strengths and limitations of each approach, the review aims to establish a standardized experimental framework for the future development of optimized sepsis models.