China is a country in which landslide disasters occur frequently, and slope movement has a direct influence on the landslide, making the analysis of slope movement and forecasting an important research direction. Currently, there is relatively limited research in the field of slope deformation analysis models. The research target is based on the reservoir slope, and the specific research targets are the Dingdong trough Zhengjiadagou slopes. From the perspective of hydrological surveying and mapping, a slope deformation analysis model is constructed. The displacement control factor is the main analysis object, while rainfall and reservoir water level are the main influencing factors. The internal structure of the slope is considered a characteristic factor affecting slope deformation and sliding. The results indicate that the displacement control factor of slope sliding under the influence of gravity is related to the variation of reservoir water level, with the reservoir water level being the main influencing factor. The effect of rainfall on slope deformation is not significant. Using the models of metabolic GM (1, 1), new information GM (1, 1), and GM (1, 1) to predict the deformation trend of the three slopes, of which the average error is 5.45%, 5.85%, and 7.48%. The results indicate that constructing a reservoir slope analysis model from the perspective of hydrological surveying provides a visual advantage in studying slope deformation issues using the model analysis approach, and the metabolism GM (1, 1) model in the slope deformation trend prediction accuracy is higher. This paper provides theoretical guidance and instance reference for the slope instance research.