The present invention provides a system and method of merchandise security. The system includes a security device, comprising at least a first communication interface, configured to be capable of simultaneously communicating with one or more controllers. A controller, comprising at least a second communication interface configured to be capable of communicating with one or more security devices simultaneously. The method uses a controller with system identity number to initialize the security device which directly or indirectly attached to the merchandise, and to operate the initialized device. The present invention can realize communication between the security device and the controller through a wireless channel, in the communication process, through the generation of the system identity number, the security device can simultaneously implement the point-to-point communication and a point-to-surface communication.