With the wide application of industrial unmanned aerial vehicles in various industries, the air collision risk of unmanned aerial vehicles (UAV) integrated into traditional airspace systems has attracted much attention. Firstly, the research status of UAV air collision risk was introduced. Then several important collision risk models were analyzed and compared, the advantages and disadvantages of different models and their application scope were discussed. From the perspective of manned aircraft, the operation scenarios of UAV were classified according to the operation environment, operation types, airspace restrictions, control and service requirements; Finally, the applicability of the quantitative model of UAV air risk is discussed by combining the collision model with the operation scenario, and suggestions are put forward for future research. The research results can provide theoretical guidance for the risk assessment of UAV in the integrated airspace and help build laws and regulations system of UAV.