Flight initiation distance (FID) is defined as a distance at which an animal flees due to the presence of an approaching stimulus (such as predators and humans). It is a very common used parameter for studying the processes associated with escape decision making because it reflects the risk at which an individual is willing to take while approached by a potential predator. It is also applied for animal conservation purposes such as establishing buffer areas to minimize human disturbance. This review summarized the factors influencing the FID in birds during the predator-prey interaction, with mainly three categories classified as environmental factors (e.g., distance to refuge and habitat openness), bird′s own factors (e.g., life history, body size and group size) and predator′s factors (e.g., direction of approach and approach speed). Moreover, urbanization also affects the FID in birds, with smaller FID in the cities, caused by habituation, local adaptation, and habitat selection. Knowledge and understanding of the factors affecting FID in birds may play a key role in escape behavior research and promoting the coexistence of human being and birds. Most studies on FID of birds were focused on behavioral observation or the effect of single factor in China, we suggest future works should strive to test targeted interactions between factors to understand how species weigh the importance of each factor in different situations.