The invention provides a sensor device and a work method of the sensor device. The sensor device comprises a sensor node and an RFID (radio frequency identification) tag, wherein the sensor node comprises a storer and a CPU (central processing unit); the sensor node can work under a break mode or a sequential mode; the RFID tag is connected to an input-output port of the sensor node, and by coupling a DMA (Direct Memory Access) channel with the storer of the sensor node, the sensor node can be put under a low-power mode no matter whether the RFID tag is communicating or not; the RFID tag can enable the sensor node to switch between the high-power mode and the low-power mode by transmitting instructions to the sensor node; the RFID tag can enable the sensor node to break to execute the latest instructions by transmitting different instructions; and the RFID tag stores data from an RFID reader in response to first polling from the RFID reader, and transmits stored measurement data of the sensor node to the RFID reader in response to second polling from the RFID reader. The sensor device and the work method thereof process instructions from the RFID reader-writer in a simple and flexible manner, and prolong the use of the battery-powered sensor node.