Active structure of RFID tag with the frequency of 2.4 GHz is put forward; the software and hardware circuit is designed as well. In the design, MSP430F2122 single chip microcomputer and CYRF6936 RF chip are selected on the purpose of ultra low power consumption. Long recognition distance, high stability, ultra low power consumption and anti jamming capability are the main superiority of the design, based on which the tag is available to different kinds of complex environments such as underground coal mining, oil exploitation and so on.