In this paper, a ±45° dual-polarized microstrip antenna with high cross-polarization isolation is designed. By using the differential feeding combined with coupling feed feed way, improved the antenna port isolation and cross polarization isolation ratio. The bandwidth is increased by loading H-shaped gaps and using short-circuit column grounding measures. The simulation results show that within 24 GHZ - 28 GHZ frequency band, which can realize gain of the antenna is greater than 5.87dBi, VSWR are less than 2, port isolation degree is more than 42 dB, cross polarization isolation degree greater than 30 dB .