In the process of water alternating gas (WAG) injection in a CO2 test area, CO2 hydrate freeze plugging frequently occurs in some injection wells, which seriously affects the injection time rate and displacement efficiency of the injection and production system. Based on the analysis of the hydrate formation causes and rules, a new formula system of freeze plugging removing agent integrating heat release and plugging removal was developed through laboratory research and performance evaluation. The formula introduced strong polar groups into the main agent to destroy the cage structure of the hydrate lattice, and quickly broke through the dead oil cap with the heat release effect of inorganic metal salt, with the indoor plugging removal rate of 100%, the corrosion rate less than 0.076 mm/a, and the operation period of 36 h. It has the characteristics of strong breakthrough ability for dead oil, high hydrate dissolution efficiency at low temperature, and low corrosion rate. According to the characteristics of no circulation channel and small dosage space of the target wells, combined with the performance of the new formula system of freeze plugging removing agent, the multi-round and small-displacement high-pressure soaking and plugging removal process is optimized, which effectively improves the plug removing efficiency. This technology has been used in a CO2 test area for 6 wells with a 100% success rate, an average operation period of 4 days, and a plugging removal efficiency improvement of more than 70%, ensuring the normal operation of CO2 injection wells, and providing strong technical support for the construction of CCUS demonstration zone.