Traditional land satellite communication system mostly use parabolic antenna, which is bulky and inflexible. Microtrip arraying antenna also can be used as the antenna of land satellite communication system, however, the microtrip antenna has a low gain and a large loss. In this paper, a novel waveguide horn antenna is designed. The radiation layer is perfect conductor with a octagonal hole in the center. the feeding layer is double orthogonal microstrip-feed plane to achieve bipolaron. The unit antenna size is only 21mm 21mm2.2mm. Gain of 2 2 array was 15dB. The antenna had a simple structure, small volume and high gain, particularly suitable for land satellite communications system.