Iodine contrast agent is a common contrast agent used in imaging examinations, including enhanced CT and angiography, which may use iodine contrast agent. The biggest hazard of iodine contrast agent is to cause damage to the kidney function of patients because iodine contrast agent is a hypertonic solvent, which can easily accumulate in the kidney causing renal failure. Therefore, patients should be advised to drink more water and drink appropriately to increase the excretion of contrast agent and promote the recovery of renal function. The adverse reactions of iodine contrast agent also include allergic reactions. Very few patients may develop urticaria, skin papules, itching, erythema, and in severe cases, anaphylaxis may occur, so iodine allergy test is usually done routinely when doing contrast, and epinephrine is prepared as a rescue drug, and there are rare adverse reactions such as liver damage.