To solve problems of expensive testing equipment, long-cycle analysis and being difficult to apply in daily life when detecting milk quality, and to theoretically study the milk quality testing methods based on radio frequency identification (RFID) technology, RFID tag antenna was designed to sense the quality of milk, and the impact was analyzed of different dielectric parameters of milk on the RFID resonant frequency. The designed antenna coil shows near-field gain maximum 74. 877 0 dB, and radiation efficiency 95. 1% when coupling with reader. The optimized antenna has higher sensitivity than normal commercial antennas in milk quality detection.