Disclosed are a synchronization method and device, which are used to achieve the distinction of a synchronization system and a synchronization level of a node in a V2V communication system, thereby quickly achieving the synchronization in the V2V communication system. Provided is a synchronization method, comprising: determining a synchronization priority level of a current node; and according to the synchronization priority level of the current node, determining a synchronization sequence used by the current node and a value of a distinguishing flag bit of the current node, wherein the distinguishing flag bit is used to distinguish whether the current node belongs to a GNSS synchronization system or an eNB synchronization system.