Abstract: In near-field optical storage, dynamic flying height measuring technique is a key of the theory and its application. In flying height measuring method utilizing light intensity interference principle, the position control of micro flying head has effect on measuring error. This paper presents a location system based on visual feedback, focus on its configuration. The precision of mechanical control component and imaging processing algorithm was detailed. Analysis and experiment prove that this system has a location precision of 11μm, which causes flying height measuring error less than 1nm. These parameters enable high-resolution dynamic measurement of spacing between the flying head and disk.