Abstract: The preparation of light olefins by CO₂ hydrogenation is an important way to alleviate greenhouse effect. Meanwhile, this is of great significance in improving the self-sufficiency rate of light olefin in China. However, the catalyst with high conversion rates and selectivity towards target products is a prerequisite for achieving high yields. In order to enhance the yield of light olefins, a perovskite catalyst Sr_1−xK_xFe_0.5Co_yO₃ was prepared by sol-gel method. This kind of catalyst have notable results with a CO₂ conversion rate of 53.73%, a light olefin selectivity of 40.55%, and a yield of 21.79%. The characterization of catalysts reveal that the medium-strong basic sites and oxygen vacancy concentration are enhanced with addition of Co, which promote the activation of CO₂. As a result, the conversion rate of CO₂ has been improved. The Fischer-Tropsch synthesis reaction has been promoted with the doping of K. Thereby, the selectivity of light olefin has been improved. The precipitation of active metal phases, dissociative adsorption of C-O and facilitated subsequent C-C coupling are all enhanced by the co-doped Co/K. Thereby, CO₂ conversion and light olefin selectivity are increased.