Unmanned aerial vehicle (UAV)-enabled communication is an essential component of the promising next generation networks owning to its advantages of high maneuverability and low cost. However, the limited onboard energy and weak communication ability of the UAV, as well as the open nature of the wireless networks, may result in the insufficient service time, low coverage and worrying security. Collaborative beam-forming is an effective technique for boosting the communication performance of the multi-antenna systems, which is able to achieve an energy-efficient, long-range and secure transmission. In this work, we focus on the UAV-enabled collaborative beamforming via swarm intelligence approaches. First, we present some preliminaries such as collaborative beamforming, swarm intelligence and multi-objective optimization, and artificial intelligence (AI)-enabled UAV swarm networks. Then, several typical applications of UAV-enabled collaborative beamforming are briefly presented. Subsequently, we propose two UAV communication schemes via collaborative beamforming to enhance communication performance. Specifically, we jointly optimize the schedules of UAVs and the communication order of multiple base stations (BSs) to achieve a secure and energy-efficient transmission. Moreover, we also deploy the UAVs and configure the communication order of the BSs for a time and energy minimization communication via collaborative beamforming. Visualization and numerical results are provided to verify the performance of the proposed schemes. Finally, we also point out some future directions worthy of further investigation.