Epinephrine is an emergency drug, which mainly agonizes alpha receptors and beta receptors. In the heart, it can cause enhanced myocardial contractility, accelerated conduction, accelerated heart rate, increased myocardial excitability, and act on the alpha receptors of vascular smooth muscle to cause vasoconstriction, while large doses of intravenous epinephrine increase both systolic and diastolic blood pressure due to the vasoconstriction response. The side effects of epinephrine include headache, irritability, insomnia, pallor and weakness, increased blood pressure, tremor and other adverse reactions. When epinephrine is used in high doses, abdominal pain and cardiac arrhythmia can occur. Epinephrine is mainly used in the treatment of cardiac arrest, bronchial asthma and anaphylaxis, etc. It is important to pay attention to the side effects of epinephrine use during treatment.