The satellite navigation signals are susceptible to interferences under a complex environment, which may result in the failure of UAV satellite positioning.An autonomous positioning technology for micro-UAVs based on multi-point constraint is proposed.Through the on-board photoelectric measurement platform, multiple ground targets are observed.By using the geometric relationship that the ground target point, image point and the camera optical center are collinear, the autonomous positioning mathematical model of the UAV is established.The UAVs own spatial position is obtained by using the least square estimation.The feasibility and robustness of the method are verified by experiments.The experimental results show that the method can obtain the position information of the UAV within the allowable error range.