With the extensive application of civil UAV technologythe practice of integrating UAV into national airspaceand executing flight missions with manned aircraft in shared airspace at low altitude has become a trend of future development.UAV “sensing and avoiding” system plays a crucial role in ensuring flight safety in the integrated airspace in the futureand the autonomous collision avoidance algorithm is a key part to ensure efficient operation of the whole system.At presentthe research on autonomous collision avoidance algorithms of the UAV has been very in-depth.The existing collision avoidance algorithms are classified based on the characteristics and mechanism of collision avoidancedifferent types of collision avoidance algorithms are introduced in detailand their advantages and limitations are expounded.Finallythe development direction of autonomous collision avoidance algorithms for UAVs is prospected.