In view of the installation error of double through holes in large components when measuring cross sections of multiple holes, a coaxial measuring device based on position sensitive detector (PSD)positioning principle is proposed, which uses pneumatic mandrel and sliding table motion device of lead screw and nut. The lead screw and nut slide table is used as the motion measurement part to collect the parameter information of the measured spot. The detailed structure design of the fixture mechanism and the parts of the PSD installation and motion device is carried out to realize the PSD translation and rotation in the hole section. At the same time, the upper computer software is constructed to realize the system login, and automatic data processing and storage. The automatic operation of the whole device requires only simple loading and unloading. The final measurement results can be visualized by LabVIEW host computer software, and the deviation between the center line of the measured hole in each location and the standard center point can be displayed in real terms, and the coaxiality can be quantified and evaluated.