Because CO2 is the main greenhouse gas, its capture and catalytic conversion are thought to be significant issues to be solved at the current time. Given the thermodynamically stable and inert nature of CO2, it is highly desirable to develop advanced catalysts to facilitate the transformation of CO2 to other high-value-added chemicals under mild conditions. Within this regard, porous organic polymers (POPs), featuring large surface areas, high thermal stabilities, diverse building blocks, and tunable porous structures, are an ideal platform for the construction of heterogeneous catalysts for CO2 conversion. Incorporating active sites that are capable of activating CO2 and/or substrates into the frameworks of POPs can facilitate CO2 conversion. In this Review, the most recent advances in the design and synthesis of POP-based heterogeneous catalysts for the conversion of CO2 are summarized. We mainly focus on the synthetic strategies researchers have used for incorporating active sites into POP frameworks to prepare heterogeneous catalysts for CO2 conversion, including N-doping, metalation, and ionic functionalization. Problems remaining to be addressed in this field are analyzed, and future directions are outlined.