An ultra-wideband(UWB) dual-polarized corrugated horn antenna is proposed in this paper. The operating frequency band is 24-50GHz, covering the 5G communication frequency band. This antenna makes up for the deficiency of the traditional horn antenna in bandwidth and radiation characteristics. The structure of quad-ridge corrugated horn antenna and orthomode transducer(OMT) is used to realize the UWB, dual-polarization and high cross polarization isolation. In practical application, the waveguide coaxial transfer structure is required for installation and connection. The measured VSWR results are 2.2 Max., the port isolation results are -30dB Max. The proposed antenna has good far field characteristics. The gain results are 20dB Typ. and the cross polarization isolation are - 35dB Max. The proposed horn antenna has been processed and applied in the practical systems.