The Hariti Statue in Fowan of the Beishan Rock Carvings at Dazu has a very high cultural, historical and artistic value, however its weathering is serious, and the statue of the long-term preservation is facing a serious challenge. In order to study the weathering mechanism of the Hariti Statue, this paper made a detailed investigation on the diseases of statues. The samples of weathered dust were collected from the surface of the rock mass of the Hariti Statue for X-ray diffraction (XRD) and ion chromatography (IC) analysis, which tested the mineral composition and the content and composition of the soluble salts. The meteorological parameters such as air temperature, relative humidity, rainfall and the concentration of atmospheric pollutants such as sulfur dioxide (SO₂), nitrogen dioxide (NO₂), 2.5-micrometer Particulate Matter (PM_2.5), inhalable particles (PM₁₀) in the study area were monitored for a long time by the integrated meteorological and air quality monitoring station. The results of disease investigation showed that dust and chalking flaking were the most important diseases to the stone and painting of the statue. XRD test showed that the mineral composition was dominated by quartz, plagioclase feldspar and gypsum. These mineral components have a large degree of weathering, and some components such as gypsum are susceptible to the decomposition under chemical weathering by various acids. IC analysis showed high content of sulfate ion (SO₄^2-), nitrate Ion (NO^3-) and chloride ion (Cl^-), whose acidic corrosion and salinization accelerate the weathering and disintegration of the artifactual minerals. The results of environmental monitoring showed that the area was in the high humidity range of 70%-80%. The air temperature fluctuates greatly depending on the season, and the maximum temperature in the area of the statue is over 40 ℃ in summer. The hot and humid environment is apt to induce the weathering of rock cultural heritage, and when the temperature fluctuation is accompanied by the change of humidity, the risk of weathering would be increased. The air pollution in the statue area is serious, among which atmospheric particulate matters are the most important pollution factors. The chemicals in particulate matter along with acidic gaseous pollutants such as SO₂ and NO₂ will catalyze the erosion of minerals on rock surfaces.