The chemical transformation of CO₂ and epoxides into cyclic carbonates has been receiving much attention and is one of the successful examples for CO₂ utilization as carbon resource. Many catalysts containing halide anions have been explored and exhibit excellent catalytic activity. However, halogen salt is generally toxic and corrosive to reactors. From a green chemistry perspective, it is more attractive to develop a halogen-free catalyst with excellent performance. Herein, a review of recent research progress of halogen-free catalysts in the cycloaddition of CO₂ and epoxide is presented. According to previous experimental and theoretical works, two possible strategies for achieving the halogen-free process were summarized. The relationship between catalytic activity and catalyst structure, the mechanism of CO₂ activation should be both studied deeply combined with experimental results and DFT calculation, which can guide the design of new catalysts and realize halogen-free process under mild reaction conditions.