As the basis of designing and implementing a cyber-physical system (CPS), architecture research is very important but still at preliminary stage. Since CPS includes physical components, time and space constraints seriously challenge architecture study. In this paper, a service-oriented architecture of CPS was presented. Further, a two-way time synchronization algorithm for CPS service composition was put forward. And a formal method, for judging if actual CPS service meets space constraints, was suggested, which was based on space-π-calculus proposed. Finally, a case study was performed and CPS business process designed by the model and the proposed methods could run well. The application of research conclusion implies that it has rationality and feasibility. As the basis of designing and implementing a cyber-physical system (CPS), architecture research is very important but still at preliminary stage. Since CPS includes physical components, time and space constraints seriously challenge architecture study. In this paper, a service-oriented Further, a two-way time synchronization algorithm for CPS service composition was put forward. And a formal method for judging if actual CPS service meets space constraints, was suggested, which was based on space-π-calculus proposed. Finally, a case study was performed and CPS business process designed by the model and the proposed method could run well. The application of research conclusion implies that it has rationality and feasibility.