Detection device and detection method for visual axis shake and focal length value of optical system

The present invention relates to a detection apparatus and method for detecting the visual axis of the optical system and the focus value of the shaking, the visual axis detecting means by a projection apparatus, a photodetector and a timing control unit, where the visual axis of the projection device and a light source drive controller, points a reticle, the illumination light source and collimating mirrors; synchronous control means and the projection of the visual axis of the photodetector by the timing control means, when the frame image of the projection target image has not only record extraction target miss distance, after the frame image interpretation, to achieve visual axis detecting optical system and the position of the combined focal length value; no projection target image on the image for real-time recording and extracting target miss distance, miss distance feed servo system for automatic target tracking. The present invention solves the problem in the conventional automatic tracking theodolite targets, since the amount of the extract on a target image projected on the target crosshair off, can not detect the fluctuation of visual axis and focus variation theodolite optical system.