Unmanned aerial vehicles (UAVs) as relaying can establish a reliable and efficient data transmission link and is used in the field of emergency communications. By considering the interferences at the amplify-and-forward UAV relays, two beamforming (BF) strategies are proposed to improve the communication quality and performance. The expressions of signal-to-interference-and-noise ratio and achievable rate at the ground receiver are first presented. Then, two optimization problems are formulated, namely total relay transmit power minimization and achievable rate maximization, and the corresponding BF schemes is designed to obtain the optimal BF analytical expressions. Finally, the effectiveness and validity of the proposed BF schemes are verified by simulations.