1. A system comprising an active radio frequency identification (RFID) tag, comprising: a control processor; a coordinator, configured to uninterruptedly and repeatedly transmit a wakeup instruction on a first channel; and a reader/writer, connected to the control processor, and configured to establish communication with the active RFID tag on a second channel after the active RFID tag receives the wakeup instruction, and transmit an action instruction index to the active RFID tag; wherein the active RFID tag comprises: a receiver, configured to receive the wakeup instruction during a time period of an interception state from the coordinator and receive the action instruction index from the reader/writer; and a processor, configured to store a preset index-action mapping relationship, to wake up according to the wakeup instruction and search out an action instruction corresponding to the action instruction index from the index-action mapping relationship, and execute an operation in response to the action instruction; wherein the action instruction index comprises an action code and corresponding parameters, and the action instruction comprises a control function; wherein the corresponding parameters comprise at least one of: a signal transmission channel, a signal transmission interval, a transmit power, signal transmission times, a sequence number of an element whose parameter is read by the active RFID tag, and a sequence number of the reader/writer receiving a signal transmitted by the active RFID tag.