Cerebral infarction belongs to the category of stroke in Chinese medicine. Leeches, with a small poison, have a certain effect on stroke caused by blood stasis, but the efficacy of single Chinese medicine is limited, clinically need to be used with other Chinese medicines after identification by a traditional Chinese medicine practitioner. Leeches, with the effect of breaking blood stasis and promoting menstruation, expelling blood stasis and eliminating symptoms. It is mainly used for treating blood stasis and menstrual closure, obstruction in the abdomen (tangible or intangible lumps in the abdomen with distension and pain), bruises and injuries, pain in the heart and abdomen. Adverse reactions include skin rash, itching, nausea, vomiting, abdominal pain, diarrhea, gastrointestinal bleeding and even coma in some patients, and is contraindicated in allergy. Weakness and blood deficiency, pregnant women, women during menstruation and those with bleeding tendency are prohibited. If there is any discomfort, it is recommended to consult a doctor in time. If medication is needed, it should be identified by a doctor and follow the doctor’s instructions for standardized treatment.