Abstract: In mechanical machining, high precision requirements for small and medium-sized holes in parts are common, and reaming is one of the ways to improve the accuracy of small and medium-sized holes. In the reaming process, quality problems such as aperture shape and position accuracy error, hole wall damage, and surface roughness, etc. often appear. In this paper, based on the practical experience, the cutting test is carried out on the INDEX turn-milling compound machine tool, and the reamer structure, cutting parameters, clamping alignment and coolant selection are improved; then, methods and measures to control the reaming quality are put forward. It provides a reference for the similar precision small hole parts.