In order to better grasp the long-term behavior and evolution law of dam deformation, the multifractal theory was applied to the analysis of measured data of dam deformation under the premise of considering the correlation between displacement and environmental quantity. Taking the deformation analysis of a concrete gravity dam as an example, the multi-scale sliding time window was used to eliminate the pseudo fluctuation generated by the traditional multifractal sub interval division. The multifractal characteristics of the correlation between displacement and environmental quantity were characterized by the multifractal detrended cross-correlation analysis(MF-DCCA). Furthermore, the multifractal asymmetric detrended cross-correlation analysis(MF-A-DCCA)was used to further analyze the volatility, asymmetry and long-range correlation of the original displacement sequence, positive trend and negative trend. The multifractal characteristics of displacement under the influence of environmental factors were described from two aspects of overall fluctuation and local trend of displacement. From the analysis results, the deformation behavior of the dam is good and the multifractal characteristics of displacement are obviously affected by environmental factors. The change of reservoir water level is the main cause for the multifractal characteristics of the horizontal displacement.