In this paper, as a practical approach to building a human-centered cyber-physical system (CPS), we propose a software platform that integrates hardware and software materials to realize a human digital twin (HDT) including model construction, data acquisition, analysis, and intervention in terms of the physical load and physical capabilities of humans. Furthermore, as a case study of this platform in industrial applications, we introduce an example of a human-centered CPS in which humans and robots work together to realize better human workability and production line productivity within the system.