Abstract: To solve the problem of online measuring micro-target parts in assembling process, a micro-vision measuring system was designed and developed in this paper. The composition of miro-vision system, implementation of micro image capturing, image preprocessing, and character measurement were described. In the preprocessing, a new refiltering and denoising algorithm and a character measuring algorithm were presented for microtarget parts. Then, the system was used to measure the microtarget parts such as Al sidestep sample, and hohlraums. Experimental results indicate that proposed system can measure the geometric characters and sample positions in real time, high speed and high precision for target parts. When measuring field of view is 3 mm, the geometric measuring precision and angle precision are less than 3 μm and 01°, respectively, which shows proposed system is suitable for the assembling process of microtarget part.