Objective To investigate the effect of continuous blood purification (CBP) on peripheral blood monocyte membrane CD14 (mCD14) expression and inflammatory response in patients with traumatic sepsis Methods A retrospective case control study was conducted on the clinical data of 50 patients with severe sepsis after trauma treated between January 2015 and December 2016. There were 34 males and 16 females, with an average age of 45.37 years (range, 16-73 years). Patients were divided into CBP group (25 cases) and non-CBP group (25 cases) according to whether they agreed to receive CBP treatment. The peripheral blood samples were collected at 0, 12, 24, 48, and 72 hours after treatment, and the mCD14 and leukocyte elastase (HLE) expressions were detected by flow cytometry and by ELISA, respectively. The peripheral blood mononuclear cells were isolated from the two groups 24 h after treatment and cultured in vitro. The variations of mCD14 expression in mononuclear cells were measured at 4, 8, 12, 24, 48, and 72 h after stimulation with lipopolysaccharide (LPS). The expression levels of tumor necrosis factor (TNF) -a, interleukin (IL) -6, and IL-10 in mononuclear cells were detected by ELISA. Results At 12, 24, 48, and 72 hours after treatment, the leukocyte elastase levels in the two groups were lower than those before treatment (P ＜ 0.01), and the decrease in CBP group was significantly greater than that of non CBP group(P＜0.01). At 12, 24, 48, and 72 hours after treatment, the mCD14 levels in both groups were up-regulated before treatment (P ＜0.01), and the increase in CBP group was significantly greater than that of non CBP group (P ＜ 0.01). The mCD14 expressions before treatment, 4 h after treatment, and 8 h after treatment in CBP group were all higher than those in non CBP group at the same time points. At 4, 8, 12, 24, and 48 hours after the re-stimulation with LPS on the mononuclear cells in both groups, the levels of TNF-α and IL-6 in CBP group were significantly higher than those in non-CBP group (P ＜0.01), and there was no significant difference in IL-10 levels between the two groups (P ＞0.05). Conclusions CBP treatment can increase monocyte mCD14 expressions through eliminating inflammatory factors and pro-inflammatory mediators and reducing HLE directly or indirectly in patients with traumatic sepsis. When the body is stimulated again, its anti-inflammatory response ability is markedly stronger than that of patients who have not received CBP treatment.