Objective To investigate the clinical effect and mechanism of action of Xuanbai Chengqi Decoction in the treatment of patients with pneumonia-induced sepsis. Methods A total of 84 patients with pneumonia-induced sepsis were randomly divided into control group and treatment group, with 42 patients in each group. The patients in the control group were given conventional Western medicine treatment alone, and those in the treatment group were given Xuanbai Chengqi Decoction in addition to the conventional Western medicine treatment. The two groups were compared in terms of lactic acid (Lac) concentration, superior vena cava oxygen saturation (ScvO2), procalcitonin (PCT) level, CURB-65 (confusion, urea, respiratory rate, blood pressure, age ≥65) community-acquired pneumonia score, and sequential organ failure assessment (SOFA) score before and after treatment. Results After treatment, both groups had significant reductions in Lac and PCT (P<0.05) and a significant increase in ScvO2 (P<0.05), and compared with the control group, the treatment group had a significantly greater reduction in Lac and a significantly greater increase in ScvO2 (P<0.05). Both groups had significant reductions in CURB-65 and SOFA scores after treatment (P<0.05), and the treatment group had significantly greater reductions than the control group (P<0.05). Conclusion Xuanbai Chengqi Decoction has a good clinical effect in the treatment of patients with pneumonia-induced sepsis and can improve their perfusion index and reduce inflammatory response.