The invention discloses an obstacle avoidance method for a Schwartz inequality-based aircraft. The method comprises the following specific steps: establishing a vertical plane obstacle avoidance coordinate system including the aircraft and an obstacle, and determining the coordinates of the aircraft and the obstacle in the vertical plane obstacle avoidance coordinate system; determining the distance between the aircraft and the obstacle, and the remaining flight time after obstacle avoidance; and resolving the normal overload instruction in a real-time manner according to the response frequency of the aircraft's actuator, wherein the aircraft's actuator works according to the normal overload instruction until the obstacle avoidance is successful. According to the invention, less external information needs to be obtained, that is, during the obstacle avoidance process, the aircraft only needs to obtain the coordinate information of a position relative to the obstacle.