Objective To investigate the clinical efficacy of early continuous renal replacement therapy (CRRT) combined with intensive intervention in the treatment of severe communityacquired pneumonia (SCAP) complicated with sepsis. Methods 90 cases of SCAP complicated with sepsis in our hospital from January 2016 to December 2019 were selected as the research objects and were randomly divided into observation group (n=45) and control group (n=45). The control group was treated with cluster intervention, and the observation group was treated with early CRRT on the basis of the control group. Before and after treatment, the levels of serum inflammatory indexes ［tumor necrosis factor (TNF)α, procalcitonin (PCT), C reactive protein (CRP)], serum oxidative stress indexes (SOD, MDA), immune function indexes (CD4+/CD8+ and serum immunoglobulin IgA and IgG concentrations were compared between the two groups before and after treatment Changes and related scores ［acute physiology and chronic health score system Ⅱ (APACHE-Ⅱ), sequential organ failure assessment (sofa) score］ changes. The clinical outcome indexes of the two groups were statistically analyzed. Results The total effective rate of the observation group (9111%) was significantly higher than that of the control group (73.33%). After treatment, the concentrations of TNF α, PCT and CRP in the two groups were significantly lower than those before treatment, and the decrease in the observation group was more significant (P＜0.05). After treatment, the levels of SOD and MDA in the two groups were significantly increased, and the level of MDA in the observation group was significantly improved (P＜0.05). After treatment, the ratio of CD4+/CD8+ and serum IgA and IgG levels in the two groups were significantly higher than those before treatment, and the increase in the observation group was more significant (P＜0.05). After treatment, Apache Ⅱ score and SOFA score of the two groups were significantly lower than those of the control group (P＜0.05). The duration of mechanical ventilation and ICU stay in the observation group were significantly shorter than those in the control group (P＜0.05). The 28 day mortality of the observation group was lower than that of the control group, but the difference was not statistically significant (P＞0.05). Conclusion Early combined CRRT intervention can significantly reduce the excessive inflammatory reaction and oxidative stress in patients with SCAP complicated with Sepsis, enhance the immune function and improve the clinical outcome.