The potential for uranium exploration in the Miaoershan area of Guangxi is enormous, but part of the local strataformations are complex, with large thickness of water- sensitive and broken formations. During drilling construction, difficulties such as hole wall collapse orand excessively large boresuper diameter occur frequently, leading to frequent accidents in the hole, which and seriously affecting the construction progress. Therefore, mineral composition and microscopic characteristics of water sensitive cores in the area were analyzed. The lithology analysis results show that there are a large number amount of clay minerals such as Montmorillonitemontmorillonite, Kaolinitekaolinite, hydromica, etc. in the water water-sensitive formationsstratum, and the microcracks are developed with serious hydration expansion. To solve above problems, A new type materialsof with film forming and wall protecting functions on flushing fluid system waswere optimized through indoor evaluation experiments, and a flushing drilling fluid system with good wall protection performance was further developed, which consists of 5% film-forming agent A, 3% film-forming agent B, 1.5% modified asphalt, 1% plugging agent while drilling, 1%sealing agent, 0.6% viscosifier, 0.2% coating agent. The results indicate that the film forming solution The API filtration loss of this drilling fluid is 5-8mL, and the relative expansion reduction rate reaches over 87%. This drilling fluid can effectively inhibit hydration expansion of the water-sensitive formations,hydration and the wall protection effect is significant. This technology has been successfully applied in three boreholes in the Miaoershan area, smoothly successfully drilling through water water-sensitive formations without any problems such as core dispersion or hole wall collapse. Good application results have been achieved, and a film forming and wall protection flushing drilling fluid technology has been preliminarily formed for water water-sensitive formations in this area.