Abstract: Objective To explore the effect of intrathecal injection of antibiotics on the prevention of intracranial infection after craniocerebral injury.Methods A total of 260 patients with intracranial infection after brain injury were randomly divided into control group and observation group.The control group was given normal saline 6 mL to replace cerebrospinal fluid,while the observation group was given intrathecal ceftazidime 0.08 g in 6 mL saline solution to replace cerebrospinal fluid.Clinical outcomes and the disease-related factors in CSF and blood were compared.Results The incidence rate of intracranial infection in the observation group was 9.23％,which was significantly lower than 31.54％ in the control group (P ＜ 0.05).One and three days after treatment,the levels of PCT and WBC in cerebrospinal fluid of the observation group were significantly lower than those of the control group,while the levels of chloride and glucose were significantly higher than those of the control group (P ＜ 0.05).The serum levels of PCT,TNF-α,IL-13,IL-6 and hs-CRP in the observation group were significantly lower than those in the control group (P ＜ 0.05).Conclusion Intrathecal injection of antibiotics can effectively inhibit the inflammatory state of patients with brain injury and reduce the incidence rate of intracranial infection.