It is well known that UHF RFID, one of the key technologies of Internet of Things, is becoming the mainstream research of RFID applications. In a RFID system, reader plays an important role, however, RFID reader with only one channel often cannot satisfy the application requirements due to the complicated working environment. This study introduces a novel design solution of Four-channel RFID reader based on Impinj R2000, Atmel's AT91SAM7S256-MU is chosen as the microcontroller. Moreover, concepts and methods of the hardware design, such as components selection, design of schematic circuit diagram and PCB, etc. are expatiated in the paper. According to the testing results, when the transmit power is set to be 25dBm, the reader can achieve reading in a round-robin manner excellently and the readable range for passive tags can reach 2.5m.