This project is a gas separation unit for the 100,000-ton/year olefin catalytic cracking plant ， aiming to recover high-value hydrogen resources from the cracking tail gas. The project adopts the pressure swing adsorption (PSA) hydrogen extraction technology specifically designed for low-hydrogen gas sources. The hydrogen content in the raw gas processed is only 17%, making it a typical case of low-concentration hydrogen recovery in the industry. The designed processing capacity of the device is 12,000 Nm³/h, and it adopts a ten-tower PSA process configuration. The product hydrogen purity reaches 99.9%, and the hydrogen recovery rate exceeds 85%. The PSA system uses a unique adsorbent ratio and timing control strategy to ensure efficient hydrogen recovery even under low hydrogen concentration conditions. The on-site construction period is 6 months, and the modular design is adopted, enabling factory prefabrication and rapid on-site installation. Since its commissioning in 2020, this device has recovered over 80 million Nm³ of hydrogen annually, significantly reducing the material consumption of the olefin production plant and enhancing the overall economic benefits.