Honeybees are losing their habitat due to invasive species such as Asian hornets. To prevent invasion, an autonomous robot system that can search for habitats while tracking Asian hornets is required. This study proposes a multi-antenna-based insect tracking system using an unmanned aerial vehicle (UAV). The proposed system measures received signal strength intensity (RSSI) using a radio telemetry method, and the measurement noise is reduced by the finite impulse response (FIR) filter. Based on the multiple radio sources extracted from the multi-antenna, the position of the tracking target is estimated using triangulation. To evaluate the performance of the developed system, localization simulations were conducted based on the dynamics simulator Coppeliasim and robot operating system (ROS). The experiments were designed with two cases: 1) the static state and 2) the dynamic state of the Asian hornet. The performance of localization errors was compared with the Kalman filter-based single-antenna system developed in our previous study. Experiments results showed that the localization error of the proposed system was within about 10 m when the error in height was not considered, and tracking accuracy was improved by about 58.72%~58.87% compared with the previous system, and 77.14~78.98% considering the localization error for height.