Aiming at the requirement of uniform and normative description of equipment system of systems (SoS) when heterogeneous equipment cooperate to complete tasks, the semantic architecture and method of equipment SoS and its dynamic reconfiguration for task completion are proposed based on the application purpose of SoS. Based on the essential requirement of “mission-oriented” of equipment system-of-systems, the mission model is proposed as the semantic description paradigm of equipment system-of-systems, and its framework and composition are proposed. A prototype implementation method of the mission model description framework is proposed, which includes the realization of mission model prototype ontology and dynamic control mechanism, and the standardized description of equipment system of systems and its dynamic reconfiguration process. The war game example shows that the task model has the feasibility of the description framework.