This paper outlines the DEMO design and related R&D activities in SWIP.The basic definition and development strategy of the DEMO plant based on the Chinese fusion energy development program are presented briefly.An updated conceptual design based on the HCSB-DEMO is performed recently.A helium-cooled blanket system with ceramic breeder,the structure material of low activation ferritic steel and Be neutron multiplier are adopted in conceptual design.The design parameters,preliminary analyses and the basic structure of HCCB-DEMO reactor are introduced.The related R&D progress on structure material,function materials,fabrication technologies of components for DEMO are also introduced briefly.