Abstract: A novel dual-polarization array antenna with low sidelobe is designed.The element antennas use pyramid horns，which realize dual-polarization radiation by orthogonal feed probes in different layers， and solve the problem of wide beam with low sidelobe by using dual choke slot.In the design of array feed，Taylor weighting is realized by using air coaxial line network，and reversed phase feeding technique is used to improve the performance such as polarization isolation and cross polarization.The measured results indicate that the return loss is less than -35 dB at 9.5 GHz±500 MHz， the sidelobe level is less than -26 dB in the Azimuth and elevation patterns， the polarization port isolation is less than -30 dB， and the cross polarization level is less than -35 dB.