With the in‑depth study of gut microbiota, its role in the nervous system and cognitive function has gradually attracted increasing attention. Scientists found that microbiota living in the intestinal tract can develop two‑way communication with the brain through the intestinal barrier, namely the 'microbiota‑gut‑brain axis'. Gut microbiota can affect the cognitive function and behavior of the host through the 'microbiota‑gut‑brain axis'. Postoperative cognitive dysfunction (POCD) is a common complication after surgery and anesthesia, which refers to the symptoms of persistent memory loss, personality change or cognitive function decline after anesthesia and surgery. This article will review the relationship, mechanism, research methods and existing problems between gut microbiota and POCD. According to current studies, gut microbiota may interfere with the occurrence of POCD through neuroendocrine, immune and vagus pathways. In addition, abnormal gut microbiota composition can also damage the integrity of intestinal barrier, activate immune system, trigger systemic inflammatory reaction, and further damage the blood‑brain barrier, aggravate nerve injury, and lead to neurodegeneration. Therefore, gut microbiota is expected to become a new target and provide new thoughts for POCD treatment.