With the development of domestic prestressing technology, the post-tensioned ring anchor prestressing technology has gradually become a key technology in the construction of water conservancy tunnel projects in China. This paper mainly introduces the application of post-tensioning ring anchor prestressing construction technology in the South-to-North water transfer project through the yellow tunnel, summarizes the construction technology, operation steps and methods, quality control, etc., and provides reference and experience for the same type of ring anchor prestressing construction in the future.