In this article, we introduce a novel security mechanism, the Smart Synergy Security (3S). The mechanism uses the Set of Experience Knowledge Structure (SOEKS) and the synergy of security methods in different domains to provide the global optimal security strategy. The proposed strategy is taking into account the characteristics of information security (i.e. confidentiality, integrity, availability, controllability, and reviewability) imposed in different domains in Internet of Vehicles (IoV). The SOEKS is used to represent knowledge, and is combined with the data flow in each domain. Initial experiments demonstrate that the proposed approach is able to find the optimal solution under different conditions for multi-domain security problems in IoV.