Abstract: Space target monocular pose estimation is one of the key enabling technologies of various new space missions. At present, it mainly faces the problems of non-cooperative space target, limited on-orbit computing resources, and high precision and real-time requirements. This paper proposes a monocular pose estimation method based on PnP (Perspective-n-Point) feature point extraction for the model-known space non-cooperative targets. First, the original images collected by the monocular camera are preprocessed by distortion correction, denoising and binarization. Then, the space target lid antenna, two side sails and body are merged for center point positioning based on the Hough transform ellipse and rectangular detection algorithms. And then, the four corner points at the most edge of the two side sails are extracted by the Harris corner point detection algorithm. And then, the final pose information is estimated by the feature point matching and PnP pose solution algorithm. Finally, the performances of the method proposed in this paper are tested by building the ground experimental test platform. The results show that the proposed method can achieve high accuracy and real-time space target monocular pose estimation with limited platform computational resources.