The paper puts forward a new high-precise non-contact measuring method combining photoelectricity and machinery in limited deep cavity to detect form and position of blind hole.System is composed of high-precise drive mechanism,endoscopic optical path,precision raster part,imaging acquisition and processing part.Endoscopic optical system is moved linearly through drive mechanism in limited deep cavity,high-resolution CCD camera acquires image of blind hole,then system completes form and position measurement of blind hole through image processing.The example indicates precise reaches 10 μm.