Objective To investigate the effect of microglia activation regulated by C-X3-C motif chemokine ligand 1 (CX3CL1)- C-X3-C motif chemokine receptor 1 (CX3CR1) pathway on memory function in hemorrhagic shock/resuscitation rats.   Methods The experiment was divided into two parts. In the first part, the rats were randomly divided into sham group, model-0.5 hour group, model-1.5 hour group, model-3 hour group, 10 rats in each group. There were differences in the time of hemorrhagic shock among each group. In the second part, rats were randomly divided into control group and CX3CL1 group, 10 rats in each group. The rats in CX3CL1 group were treated with CX3CL1 protein factor (intraventricular injection), and the rats in control group were treated with saline. All rats were trained in Morris water maze experiments before model construction, and tests of Morris water maze experiments were carried out after 4 days of model construction. After completion, the whole brains were taken for HE staining and immunohistochemical staining. Cerebrospinal fluid was taken for detection of inflammatory cytokines, and hippocampus tissues were taken for Real-time PCR detection and Western blotting detection.  Results Compared with the sham group, the escape latency of rats in model group increased, the number of platform crossings and the resident time in the third quadrant decreased. The neuronal state was impaired in HE staining in model group. In addition, compared with the sham group, the expression of ionized calcium binding adaptor molecule-1 (Iba1) in the brain of the rats in model group increased, the contents of tumor necrosis factor-α(TNF-α) and interleukin(IL)-6 in the cerebrospinal fluid increased, and the M1-type microglia markers CD16, TNF-α, IL-1β and inducible nitric oxide synthase (iNOS) mRNA content increased. At the same time, compared with the sham group, the expressions of CX3CL1 and CX3CR1 in the brain of model group decreased, and the expressions of phosphorylated nuclear factor-κB（p-NF-κB）and nucleotide binding oligomerization domain(NOD) -like receptor protein 3（NLRP3）increased. However, compared with the control group, rats in CX3CL1 group had reduced escape latency, increased platform crossing times and quadrant Ⅲ resident time, and recovered neuronal states. In addition, the expression of Iba1 in the brain of CX3CL1 group decreased, the contents of TNF-α and IL-6 in the cerebrospinal fluid decreased, the mRNA contents of M1-type microglia markers like CD16, TNF-α, IL-1β and iNOS decreased, and the mRNA contents of markers of M2-type microglia glial like CD206, transforming growth factor-β(TGF-β), arginase-1 (Arg1), Chitinase 3-like protein 1(Ym 1) increased.   Conclusion  CX3CL1 can help inhibit the excessive activation of microglia, induce the polarization of microglia to M2 type, inhibit the polarization of M1 type, reduce the release of inflammatory cytokines, and alleviate the memory function damage induced by hemorrhagic shock/resuscitation.