The buried depth of pipeline is one of the key indexes for risk assessment and decision-making of prevention and control for water damage. Based on the development characteristics, and geometric shape of gullies, and the influence of gullies on oil and gas pipelines in sand pit area of pluvial fan, the evolution process of gullies was simplified into two stages, including retrogressive erosion and gully bed siltation. On this basis, the model for predicting the buried depth of pipeline was established. The predicted values were further verified by the measured buried depth of pipeline at 15 water damage points. The results show that the proportion of deviations less than 15% is 73% , which indicated that the predicted results are basically reliable. In addition, the buried depth of pipeline is positively correlated with scour gradient, siltation gradient, design buried depth, horizontal distance, and deposition thickness; however, it is negatively correlated with pit depth, original slope, and pit slope, respectively. The model can quickly predict the buried depth of pipeline under different gully bed gradient, and it can provide science and technology support for risk assessment, disaster prevention, and route selection of pipeline in sand pit area.