Chemical absorption based on organic amine is one of the effective technologies for post-combustion CO2 capture. However, the high regeneration energy consumption of the traditional organic amine process restricts its industrial application. To reduce the energy consumption of CO2 capture, phase-change absorbents came into being. This new class of absorbent can change from homogeneous phase to two immiscible phases after absorbing CO2, and CO2 is enriched in one phase. Since only the CO2-rich phase is separated for regeneration, the regeneration volume can be greatly reduced and the regeneration energy consumption of CO2 captured can be significantly reduced. Phase-change absorbents include liquid-liquid phase-change absorbents and solid-liquid phase-change absorbents. The latter absorbs CO2 to form solid precipitate that can be rapidly separated from the solution, which has become the research focus of new absorbents in recent years. According to the composition analysis, solid-liquid phase-change absorbents can be classified into three categories: organic amine non-aqueous solutions, aqueous salt solutions and ionic liquid-based solutions. Organic amine nonaqueous solution uses organic amine as the absorption active component and organic solvent as the phase separation agent, which has the advantages of fast absorption rate and low corrosiveness. However, after absorbing CO2, their solid products are prone to form sticky gel and difficult to decompose. The salt solutions, which include amino acid salt and carbonate aqueous solution or water-lean solution, have the advantages of low cost and easy availability of raw materials. However, the solid-liquid phase-change characteristics and phase separation efficiency of existing salt phase-change absorbents need to be further improved. The ionic liquid-based solutions include two kinds of systems of conventional ionic liquids (act as solvents)/organic amines (act as active components) and functionalized ionic liquids (act as active components)/organic reagents (act as solvents), which have the properties of good thermal stability and high regeneration efficiency, but ionic liquids are complex to synthesize and their cost is relatively high. In a word, compared with traditional aqueous organic amine absorbents, solid-liquid phase-change absorbents have a greater energy saving potential and can be expected to be a promising alternative for CO2 capture with high efficiency and low-energy consumption. At present, the development of solid-liquid phase-change absorbents is still in the stage of experimental research. To promote its practical application, the future work should focus on the design principle of absorbents, phase-change mechanism, thermodynamics, kinetics, and the optimization of CO2 capture process.