Direct converting of CO2 back to petrochemical feedstock has always been an important part of the carbon recirculation. However, the CO2 conversion is hardly surpassing 60% because of the insufficient catalyst performance. This technology adopted a special method to synthesize high-surface-area porous iron-based catalysts with specific surface areas over 200 m²/g, which is 4 times higher than the traditional ones. It can directly and thoroughly convert CO2 into alkanes and alkenes with an yield over 90% and a C4-C9 hydrocarbon yield of 41.7%. A ton-scale demonstration system has been built up and trial run. The system can adjust the proportion of C2-C9 products. In the future, integration of this technology with the petrochemical industry will significantly reduce the carbon footprint of downstream plastic products.