Abstract: Objective To investigate the therapeutic effect of continuous renal replacement therapy (CRRT) in the treatment of third-spacing in patients with intra-abdominal hypertension (IAH). Methods A total of 86 cases of intra-abdominal hypertension with third-space fluid shift facing inclusion criteria in our hospital between April 2015 and Mar 2017 were enrolled and divided into treatment group (43 cases) and control group (43 cases) according to the random number table method. The control group was given routine treatment, while the observation group received additional CRRT based on the routine treatment. The therapeutic effect and the changes of renal function and inflammatory factors were compared between the two groups before and after the treatment. Results The effective rate of the treatment group was 88.4%; in the control group, the effective rate was 69.8%, it was significantly lower than that of the treatment group (P < 0.05); There was no significant difference in serum creatinine (SCr) and blood urea nitrogen (BUN) between the two groups before the treatment (all P > 0.05), 3 days after the treatment. The SCr and BUN parameters of the two groups were significantly lower than those before the treatment (all P < 0.05), and the difference (decrease degree) before and after treatment in the observation group was significantly higher than that in the control group (all P < 0.05); There was no significant difference in the levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and C-reactive protein (CRP) between the two groups before treatment (all P > 0.05), 3 days after the treatment, the levels of TNF-α, IL-6 and CRP in the two groups were significantly lower than those before the treatment (all P < 0.05), and the difference (decrease degree) before and after the treatment in the observation group was significantly higher than that in the control group (all P < 0.05); There was no significant difference in intraperitoneal pressure between the two groups before the treatment (P > 0.05), but 3 days after the treatment, the intraperitoneal pressure of the two groups were significantly lower than those before the treatment (P <0.05), and the difference (decrease degree) before and after the treatment in the observation group was significantly higher than that in the control group (P < 0.05). Conclusion CRRT shows dramatic effect in the treatment of intra-abdominal hypertension patients with third spacing fluid, it can effectively reduce cell inflammatory factors and improve renal function.