The olefin cracking process (OCP process) and selective hydrogenation process (SHP process), jointly developed by Total Petrochemicals and UOP Company, are adopted, and the supporting OCP cracking catalyst and SHP hydrogenation catalyst are used. Wison Engineering (China ) Co., Ltd. is responsible for the detailed design and contract construction of the project. The C4-C8 heavy olefin products from MTO and OPU units are used as raw materials for the unit, to produce light olefin products with ethylene and propylene as target components. The unit is mainly composed of the selective hydrogenation, olefin cracking, regeneration gas compression cycle, cracking gas compressor and regeneration gas compressor, and other sections, and it has various noticeable features, such as many units, large scale, few personnel required, advanced technology, high integration degree and localization degree.