A system and a method for reusing carbon dioxide are provided. The system includes: a process apparatus configured to discharge exhaust gas containing carbon dioxide therefrom; a purifying device configured to purify the exhaust gas, and thus produce reused carbon dioxide from the exhaust gas and store the produced reused carbon dioxide; a first supply tank configured to receive the reused carbon dioxide from the purifying device; a second supply tank configured to receive the reused carbon dioxide from the first supply tank and provide the reused carbon dioxide to the process apparatus; and a blocking device configured to, based on determining that a purity of the reused carbon dioxide provided from the purifying device to the first supply tank fails to satisfy a predefined reference, block flow of the reused carbon dioxide from the purifying device to the first supply tank.