Objective To investigate the clinical effect and safety of tigecycline on in patients with complicated intra-abdominal infections. Methods 52 cases of patients with complicated intra-abdominal infection were selected and randomly divided into 2 groups.26 cases in the control group were given routine anti-infection treatment, and 26 cases in the treatment group were treated with conventional anti-infection combined with tigecycline.The CD molecules and NK cell level, serum lactate and procalcitonin levels, and the clinical efficacy and safety were compared after the treatment between two groups.Results The effective rate of control group ( 69.23%) was lower than the treatment group ( 92.31%) with statistical significance (P<0.05), the levels of CD3 +, CD4 +/CD8 +, CD4 +and NK cells of the treatment group after treatment were higher than the control group, the level of CD8 +was lower than the control group after treatment, procalcitonin and serum lactate levels were lower than the control group, with statistical significance ( P<0.05 ) , there was no difference in adverse reactions between the two groups.Conclusion Tigecycline could improve the therapeutic effect of complicated intra-abdominal infections, reduce the lactate and procalcitonin levels with high safety.