In order to systematically characterize the mechanical properties of each mineral component in the red mudstone in Hechi area, Guangxi Province, the nanoindentation technology is used to study the mechanical properties of red mudstone samples under four peak loads. According to the test resuts of a X-ray diffractometer, an optical microscope and other instruments, the measurement of each test point are linked with each mineral component correspondingly. The results show that the red mudstone in Hechi area of Guangxi Province has high heterogeneity, it is mainly composed of SiO2, Al2O3 and Fe2O3, with quartz, plagioclase, muscovite, etc. as the main mineral components. The clay minerals and other mineral components are closely and irregularly arranged. The mudstone load-indentation depth curve of single nanoindentation test has a high degree of discretization, but the average maximum indentation depth and plastic deformation of 12 measuring points under each group of load present the same pattern, which is the greater the load, the greater the indentation depth. When the load is relatively small, the elastic modulus of each measuring point is in a good linear correlation with the hardness. The quartz in the mudstone has the highest strength and the best mechanical properties, followed by plagioclase; whereas muscovite and clay minerals have the worst mechanical properties. Because the red mudstone is characterized by porous and fractured structure, the average elastic modulus of its clay minerals is lower than that in other types of rocks, which is also the reason why the red mudstone is prone to fractures and easy to disintegrate in contact of water.