Synthetic aperture ladar is a generalization of the synthetic aperture technique in the field of laser coherent detection with a higher resolution compared to the conventional synthetic aperture ladar.Compared with airborne and ground-based applications, there was no atmospheric turbulence and mechanical vibration in space. It′s very suitable for the application of synthetic aperture ladar. At the same time, synthetic aperture ladar′s advantages that the resolution doesn′t change with distance change can also be conducive to large scale spatial distance detection. Non-cooperative target high resolution imaging model was established with analysis on the key parameters of the system and a geostationary orbit system was designed. The system engineering need further breakthrough key technology. Combined with theoretical analysis, a scaling model validation experiment was carried on with space satellite motion simulated by the turntable and the cross-range resolution of 1 mm was obtained, proving the practicability of the system analysis and rationality of the system. The space-based synthetic aperture ladar technology has great promotion in applications.