The present disclosure discloses an obstacle avoidance method and apparatus and an unmanned aerial vehicle. The method includes: obtaining detection images of at least two different focal lengths from a camera apparatus; determining, according to the detection images of the at least two different focal lengths, that an obstacle exists in a detection area; and obtaining position information of the obstacle according to the detection images of the at least two different focal lengths. Because the camera apparatus performs a zooming operation quickly, it's no need to precisely obtain position and attitude information by using a Global Positioning System (GPS) and an onboard inertial device, which avoids measurement interference and a positioning error caused by the inertial device, thereby improves calculation precision.