Non-ionic iodine contrast agents are usually used for clinical contrast examinations and are excreted more rapidly than ionic contrast agents, and can be completely excreted about 24 hours after intravenous injection. The contrast agents used in contrast examinations are usually non-ionic iodine contrast agents such as Onepac and Uvexan, which reduce the burden on the kidneys to a certain extent. This is because the contrast agent is mainly metabolized by the kidneys, and the speed of kidney metabolism is related to kidney function and water intake. The better the kidney function, the faster the metabolism rate of contrast agent; in patients with poor kidney function, the metabolism rate of contrast agent will also be slower; patients with obvious poor kidney function are prohibited from performing contrast examination. In addition, drinking more water after contrast helps to speed up the discharge of contrast agent from the body. It is important to observe whether there is any iodine allergic reaction in contrast examination. Once iodine contrast agent allergy occurs, active measures should be taken for treatment, usually using anti-allergic drugs, pressure-raising drugs and hormonal drugs to relieve allergic symptoms.