UAV (Unmanned aerial vehicle) swarms hold broad application prospects in both military and civilian domains, and are developing rapidly. Communication and networking technologies tailored for swarms are crucial for enabling their formation systems and synergistic effectiveness. To this end, key technologies, research status, and development trends in UAV swarm communication and networking were systematically reviewed. Specifically, typical application scenarios and networking requirements of UAV swarms were analyzed. Key challenges and corresponding solutions were thoroughly discussed at the physical layer, data link layer, and network layer, respectively. Furthermore, leveraging the cyber-physical fusion characteristics of UAVs, the deep coupling effects among communication, computation, and control, along with their joint optimization methods, were analyzed and summarized. Regarding intelligent empowerment, the intelligent architecture integrating "intent understanding, environment adaptation, and resource scheduling" as a trinity, alongside the latest research progress, were examined. For engineering applications, critical issues such as high-frequency band communication hardware optimization and antenna lightweighting were explored. The prospects for integrating UAV swarms into future integrated space-air-ground networks and the directions for next-step development were outlined. This review aimed to provide references for top-level planning and design, as well as for future research directions regarding key technological breakthroughs in the field of UAV swarm communication and networking.