Abstract: CO₂-enhanced coalbed methane (CO₂−ECBM) recovery is an important synergistic approach that simultaneously boosts methane production and enables CO₂ geological storage, offering dual benefits of energy development and emission reduction in the context of carbon neutrality. To systematically review the development trajectory and core bottlenecks of the technology, an overview is presented from four dimensions: experimental research, numerical simulation, field measurement and monitoring technology. Experimentally, the influences of injection pressure, temperature, and coal rank on competitive gas adsorption, permeability evolution, and displacement efficiency are systematically analyzed. In terms of numerical simulation, the evolution from HM and THM to THMC and AHTMC multi-field coupling models is reviewed, revealing the interaction mechanisms among gas, water, thermal, mechanical, and chemical processes. For field tests, pilot cases from China, the United States, Canada, Japan, Poland, and other countries are compared, and common challenges, such as permeability reduction caused by coal matrix swelling as well as process optimization strategies like multi-branch horizontal wells and intermittent nitrogen injection are examined. Regarding monitoring technologies, a multi-level monitoring framework encompassing “downhole sensing–reservoir imaging–surface surveillance–space-air inspection” and its technical characteristics are explored. Significant progress has been made in CO₂−ECBM technology in terms of mechanistic understanding, simulation tools, engineering practice, and monitoring capabilities. However, several major bottlenecks remain: Permeability decline induced by coal adsorption swelling, insufficient adaptability under complex geological conditions, limited accuracy of multi-field coupling models, and inadequate real-time synergy of monitoring systems. Future efforts should concentrate on areas such as fully coupled numerical modeling, complex reservoir adaptation, dynamic gas injection process optimization, and intelligent monitoring and early warning, thereby steering the technology toward greater safety, efficiency, and cost-effectiveness, and providing a viable pathway for achieving carbon neutrality goals.