The formation of Ruoergai uranium mining field is extremely complex, mainly manifesting with high water sensitivity, strong broken and severe leakage, which result in high difficulty of drilling operation. In this article, combining the analysis on formation characteristics and the hole wall stability, the mud system suitable for the complex formation drilling in mining area is obtained, and good application results achieved in site. And a set of technical measures of mud maintenance and management are summarized in the application, which can be good reference for mud technology in similar complex formation drilling construction.