Abstract: The hydrogenation of CO2 to light olefins is an important technological route for hydrogen energy conversion and CO2 resource utilization under the "dual carbon" goals. This article reviews the latest progress in this field. First, thermodynamic analysis indicates that CO2 molecules are highly stable and their activation must overcome a high energy barrier. Meanwhile, olefin products are less stable than alkanes, and the olefins formed are prone to over-hydrogenation to saturated alkanes. Achieving high selectivity to light olefins is therefore the central challenge. Subsequently, two main technological routes are elaborated: the reverse water-gas shift coupled with Fischer-Tropsch synthesis (RWGS-FTO) route and the methanol-mediated (CO2-MTO) route. For the RWGS-FTO route, the discussion focuses on the dynamic evolution and synergistic mechanism of active phases (Fe3O4 and χ-Fe5C2) in iron-based catalysts. The electronic promotion effects of promoters such as alkali metals (Na, K) and transition metals (Mn, Zn, Cu), as well as the regulatory role of supports on catalytic performance, are summarized. Although this route exhibits high CO2 conversation, the product distribution is constrained by the ASF model, limiting light olefin selectivity to no more than 58%. For the methanol-mediated route, the focus is on bifunctional catalytic systems composed of metal oxides (e.g., ZnZrOx solid solutions, In2O3, and spinel oxides) and zeolites (e.g., SAPO-34, SSZ-13). The critical roles of zeolite topology, acidity, and the spatial proximity between the two components in intermediate transfer and product selectivity are analyzed. This route can break the ASF limitation and achieve over 80% light olefin selectivity, but faces the challenge of low single-pass CO2 conversion. Finally, in response to the "seesaw" problem where CO2 conversion and light olefin selectivity are difficult to balance, future directions are proposed, including the design of efficient catalysts, in-depth investigation of reaction mechanisms, and optimization of reaction processes.