A RCC gravity dam has operated for many years since being built. In order to understand the deformation of the project, in this paper, the key dam section of the RCC gravity dam is analyzed. Byusing the years of monitoring data and combining with statistical modeling methods, the anti-skidding of the dam foundation, the anti-overturning stability and the horizontal displacement of the dam are analyzed in depth. The results show that, the water pressure component of the dam foundation is 70% ~ 85%. The temperature component is about 10% ~ 20%, and the proportion of the aging component is not more than 10%.In addition, the complicated geological conditions, non-continuous rock mass and bedrock mineral species are also the main cause of dam foundation diagonal changes. The horizontal displacement of the dam foundation and the dam is greatly influenced by the reservoir water level, the water pressure components of EL675.1m and EL706.5m account for about 80% and 60%, respectively. The temperature components account for about 10% and 20%, respectively. The aging components account for about 10% and 20%. The overall deformation of the dam and dam foundation is normal.