Stereo adjustment is the key to stereo mapping of domestic optical satellite image. In recent years, the most common satellite data used for stereo mapping was the along-track stereo pairs from the tri-linear CCD mapping camera in domestic. With the improvement of satellite mobility and the measurement accuracy of orbit and attitude, using the single line array CCD camera, by side sway, to obtain across-track stereo pairs becomes possible. In this paper, the YG- 24 satellite panchromatic very high resolution (HR) images were used to obtain the across-track stereo pairs. Based on undistorted RFM, the stereo pairs were processed with affine transformation model under the condition of different number of ground control points (GCPs). The result shows that, the stereo positioning accuracy of bundle adjustment can reach 35m without GCPs; while the root mean square errors (RMSEs) of plane is 0.7m and the RMSEs of altitude is 0.9m with GCPs, which can meet the secondary accuracy requirements of 1:25000 mapping.