This paper studies monopole antenna and analyzes the principle of traditional monopole antenna and the effects of different scenarios on antenna performance. Then on basis of that a monopole antenna with new structure is proposed, which adopts triangular structure and some methods such as thickened radiator and elevated feed point. The new antenna decreases its dimension and widens its working band. Then loaded antenna is used to improve the properties of the antenna further. Then several antennas are simulated and optimized by HFSS software. The best dimensions are achieved by parameter sweep and characteristics such as radiation pattern and gain are analyzed. Then the antenna three different case simulation and analysis, are infinite ground plane, finite ground plane, , adding nails and the lamp, and its parameters to optimize it for best feature. Finally, the simulation results based on the above, a method of complex integrated structure of the tail concealed ultrashort wave antenna design. And conducted a comprehensive simulation to achieve a standing wave in the 100~400 M band is less than 2.75.