An approach about how to stitch the sub-images to produce a high accuracy metric virtual image for optical splitting field of view camera was presented utilizing the constraint condition that virtual image coordinated of corresponding points in sub-images must be equal. Firstly, based on the analyzing of CCDs installation geometry error the stitching relations were designed and the sketch of stitching parameters was given; secondly, the optimized model assisted with the image matching operator was selected, such as SIFT etc. and workflow of sub-image stitching was expounded; lastly, stitch images distortion parameters refinement were processed making use of additional parameters self-calibration technology. The proposed method was verified by one self-design and manufacturing synthesized camera, and the inner precision of stitched images is within sub-pixel level that meets completely the requirements of mapping accuracy and imaging efficiency for a digital aerial photogrammetric camera.