In order to accelerate our country's achieving the goal of "double carbon" in advance, and deeply implement the important measures of green, low-carbon and sustainable development of the chemical industry, recent studies show that adsorption-absorption coupling separation technology is expected to be a green and revolutionary separation technology for gas separation, the key to which is the development of high-performance adsorption materials. As a liquid material with permanent porosity, porous liquids (PLs) combine the advantages of liquid absorbents (e.g., easy pipeline transportation, favorable mass and heat transfer, high specific surface area, etc.) with those of solid adsorbents (e.g., high porosity) and are expected to be a new generation of green, transformative media for CO2 capture. Here, first, the developmental lineage of PLs is presented, followed by a summary and detailed discussion of the applications of PLs in CO2 adsorption, membrane separation, and catalytic conversion. And summarize the performance and advantages and disadvantages of porous liquids. Finally, the challenges and difficulties faced by PLs are presented as future trends.