Three-dimensional ultra-precision measurement technology plays a basic supporting role in improving high-end equipment manufacturing quality. With the progress of advanced manufacturing technology, improving measurement accuracy and expanding measurement range have become the key to the development of 3D ultra-precision measurement technology. In recent years, confocal 3D measurement technology has developed rapidly, and its application has gradually expanded from the biomedicine engineering to the manufacturing industry. This paper systematically introduces the research status and application progress of confocal measurement technology. The methods to improve the resolution of confocal 3D measurement and expand its measurement range are expounded from the perspective of technical principles. The relevant research results of interferometric confocal measurement, differential confocal measurement and spectral confocal measurement are compared and summarized. The application of confocal 3D measurement technology in surface profile measurement, microstructure feature size measurement and internal clearance measurement of key components are introduced in detail. On this basis, the future development direction of confocal 3D measurement technology is prospected with a view to providing technical reference for subsequent research.