Microstrip antennas are relatively small in size, low profile, light in weight, flexible in structure design and simple in manufacture, and have been widely used in wireless communication, remote sensing, navigation, radar and other systems. With the development of wireless communication technology, miniaturized, multi-band microstrip patch antenna has been widely used in wireless communication. A hexagonal tri-band microstrip antenna is designed in this paper, a 120 degree notch is made inside each vertex of the hexagonal patch, which can be effectively used for L-band and C-band applications by adjusting the geometry and size of slotting of the patch to obtain three different resonant modes. Simulation software CST is used to simulate and analyze the antenna, and it satisfies S₁₁<-10dB in the operating band. The antenna has the characteristics of simple structure, small size and good gain, which can be applied in the communication system and WiFi band.