Carbon dioxide (CO₂), a colorless, odorless, low-density negative contrast agent with no nephrotoxicity or allergic reactions, has seen increasingly widespread application in the field of vascular imaging in recent years, particularly in patients with iodine allergy or renal insufficiency. When combined with digital subtraction angiography, CO₂ angiography has demonstrated high-quality imaging in various arterial and venous sites such as the abdominal aorta, renal arteries, iliac arteries, lower limb arteries, and inferior vena cava. It has also shown safety and efficacy in clinical scenarios such as peripheral arterial disease, dialysis access evaluation, and transjugular intrahepatic portosystemic shunt procedures. This review systematically summarizes domestic and international research progress on CO₂ angiography, outlines its physicochemical properties, injection dosages and parameters, clinical indications, and imaging characteristics, and compares its image quality with that of iodine-based contrast agents. Common complications, their mechanisms, and preventive measures are also discussed. Although the image quality of CO₂ is slightly inferior to that of iodine agents, it remains sufficient for most diagnostic and therapeutic needs, with a low overall incidence of mainly mild and transient adverse effects. With the development of automated injection systems and digital variance angiography technology, CO₂ imaging quality is expected to continue improving, and its application scope is likely to expand further. Future efforts should focus on strengthening multicenter clinical research and establishing standardized operational protocols to promote the broader adoption and regulated use of this technology.