The RFID system structure and key technologies has been introduced at first in this paper. Then the hardware design method of the reader RF front end (including the design of the transmitter and receiver modules and PLL) at UHF 915 MHz has been given. The test method of the RF front end hardware system has been described at last. The results show that the design method can satisfiy the functional requirements for the reader at 915 MHz. The fabricated device has the features of stable performance, good effect and flexible configuration.