To estimate the pose of satellites in space, the docking ring component has strong rigid body characteristics and can provide a fixed circular feature, which is an important object. However, due to the need for additional constraints to estimate a single spatial circle pose on the docking ring, practical applications are greatly limited. In response to the above problems, this paper proposes a pose solution method based on a single spatial circle. First, the spatial circle is discretized into a set of 3D asymmetric specific sparse points, eliminating the strict central symmetry of the circle. Then, a two-stage pose estimation network, Hvnet, based on Hough voting is proposed to locate the 2D sparse points on the image. Finally, the position and orientation of the spatial circle are obtained by the Perspective-n-Point (PnP) algorithm. The effectiveness of the proposed method was verified through experiments, and the method was found to achieve good solution accuracy under a com-plex lighting environment. Switzerland.