Abstract: A high performance broadband and dualpolarized horn antenna, which serves as a feed source of a paraboloid antenna, is designed. The effect of the backcavity on wave station is studied. Simultaneously, the parameters of the whole antenna are optimized by CST software, and the antenna is produced and measured. The measured and simulation results show that the voltage standing wave ratio(VSWR) in whole operation frequency range is less than 2 when adaptive parameters of backcavity and position of pin are chosen. Furthermore, the other electric performances meet the demand of design.