This paper presents a compact and miniaturized biconical antenna with an asymmetric configuration. Firstly, several vital parameters which affect the performance of biconical antenna were introduced concisely. Then the basic model of biconical antenna was constructed, and the model was illustrated briefly. Finally, the simulation process was carried out with ANSOFT HFSS 15.0 by changing the flare angle of the biconical antenna. As a result, an asymmetric biconical antenna with the impedance bandwidth of 3.1GHz-10.6GHz was designed. Within this operating frequency, the antenna has an omnidirectional radiation pattern, the voltage standing wave ratio (VWRS) is less than 1.8, the return loss (S11) is less than 10.5dB, and the average gain can reach more than 5dBi, the comprehensive performance is relatively better than classic biconical antenna, it can effectively satisfies the basic requirements of antenna communication system.