Hallucinations after surgery are a normal occurrence, mostly due to the use of anesthetic drugs during surgery. In order to ensure that the surgery can be carried out smoothly, anesthetic drugs are used during the surgery. Clinically, some anesthetic drugs can cause hallucinations and delirium. For example, ketamine injection, the mechanism of action is the separation of sensation and consciousness, and the patient does not feel pain during surgery, but may experience hallucinations and delirium. It may also be due to the patient’s fear of their own disease, fear of surgery and other treatments, etc., causing the patient to become overstressed and cranial nerve fatigue triggering hallucinations, and the pharmacological factor will gradually disappear as the drug decays in the body. For hallucinations caused by tension, fear and poor rest during treatment, doctors should communicate with patients before and after surgery to explain the treatment and disease regression in a timely manner. Eliminate the patient’s tension and reduce the patient’s burden of thought and fear in order to reduce the occurrence of hallucinations and other conditions.