Thermal decomposition of metal carbonate is a common reaction in the traditional industrial processes, however, it suffers from significant CO2 emissions and high energy-cost penalties. Aided by process intensification strategy, the issues can be solved via integrating metal carbonate thermal decomposition with in-situ CO2 conversion for producing high-value chemicals. In this integrated system, reductive agents are introduced into the metal carbonate thermal decomposition process to convert the released CO2 into value-added chemicals, which greatly decreases CO2 emissions and obtains by-product profits. To promote its development, this timely review gives a state-of-the-art of this technology, especially on definition, thermodynamic and economic performance, reaction kinetics, reaction mechanisms, and potential applications. Moreover, the challenges and perspectives are discussed to guide the future researches. It is expected that this transformative technology will provide an effective solution to achieve the green and low-carbon transition for heavy emission industries.