The preparation of light olefins by CO2 hydrogenation is an important way to alleviate greenhouse effect. Meanwhile,this is ofgreat significance in improving the self-sufficiency rate of light olefin in China. However,the catalyst with high conversion rates andselectivity towards target products is a prerequisite for achieving high yields. In order to enhance the yield of light olefins,a perovskitecatalyst Sr1−xKxFe0.5CoyO3 was prepared by sol-gel method. This kind of catalyst have notable results with a CO2 conversion rate of53.73%,a light olefin selectivity of 40.55%,and a yield of 21.79%. The characterization of catalysts reveal that the medium-strong basicsites and oxygen vacancy concentration are enhanced with addition of Co,which promote the activation of CO2. As a result,theconversion rate of CO2 has been improved. The Fischer-Tropsch synthesis reaction has been promoted with the doping of K. Thereby,theselectivity of light olefin has been improved. The precipitation of active metal phases,dissociative adsorption of C-O and facilitatedsubsequent C-C coupling are all enhanced by the co-doped Co/K. Thereby,CO2 conversion and light olefin selectivity are increased.