In the space exploration, the high precision measurement of the position and orientation of the space target is still a challenging problem. In this paper, we present the key technology research on monocular vision pose measurement under complex background. First, the space target features including the center location of the light spot and the circle detection are extracted. Second, we measure the circle pose and using the points outside the circle to remove the false solution. Finally, the monocular ground testing system is established to test the performance of the proposed algorithm. The experiment results show that when the distance between the camera and the target is 1200mm, the translation error is 1.5mm and the rotate error is 0.8 degrees, respectively. © 2018 IEEE.