Abstract: Two significant features of intelligent manufacturing and model-based systems engineering (MBSE) are machine-readable and automatic reasoning capabilities of system design. However, the systems modeling langue is not sufficient to represent semantics and support automatic reasoning. First, for enabling the machine-readable capability of system modeling of complex products, based on previous work—axiomatic model-based systems engineering (A-MBSD), a semantic model named A-MBSD ontology for system design is constructed. OWL2 (Web ontology language 2) is used to specify semantic relationships of system design. Second, in order to realize automatic reasoning capability, SWRL (Semantic web rule language) is used to formally represent design axioms and rules that support functional couplings identification and optimal design solution selection. The result of system design of a satellite solar wing shows that A-MBSD Ontology can represent design semantics, and corresponding rules are able to infer functional couplings of current design and help designer to select the optimal design solution, which can avoid rework due to identifying couplings in the late experiment stage.