Abstract: The frequency of low-altitude airspace flight activities has been increasing, with various types of unmanned aerial vehicles (UAVs) and significant performance differences. These UAVs are prone to flight conflicts with buildings or other aircraft during their operations. To achieve standardized, secure, refined, and intelligent management and control of the low-altitude airspace, continuous improvement of technological means to ensure the safety of UAV operations is necessary. This involves various aspects such as conflict risk detection and safety risk assessment. This article discusses UAV trajectory prediction and intention recognition, low-altitude airspace flight conflict detection, low-altitude airspace risk assessment and early warning from three perspectives. Firstly, it summarizes the research achievements and challenges faced in UAV trajectory prediction and intention recognition. Secondly, it analyzes the advantages and disadvantages of different conflict detection methods based on the form of low-altitude airspace conflict detection. Then, focusing on low-altitude airspace risk assessment and early warning technologies, it analyzes the core issues that need to be addressed in current research. Finally, based on existing research, it proposes future development directions in UAV conflict detection and risk assessment technologies.