Abstract: The composition and technical characteristics of low altitude remote sensing system based on unmanned airship are introduced. The unmanned airship automated flies along the predefined routes and captures image sequences under the controlment of autopilot system. Geometric processing of captured low altitude stereo images, such as image matching, relative orientation, bundle block adjustment, panorama and orthoimage generation, are addressed in detail. Experimental results show that the developed system is qualified for high overlap and high resolution stereo imagery acquisition, and has good potential in large scale mapping and precise three dimensional reconstruction areas.