Abstract: The terrain of Qiaojia high fill project site in Yunnan Province is rugged and the height difference is wide. There will be problems such as large post construction settlement and differential settlement. The current calculation methods for high fill settlement, such as theoretical calculation method and numerical simulation method, need parameter input, and high fill will cause parameter spatial variability due to the source of filling materials and construction technology. The errors between the prediction results of viscoelastic model, exponential model and hyperbolic model and 30 groups of measured settlement data were compared. The results show that the prediction accuracy of viscoelastic model for high fill settlement is obviously better than the other two models. The viscoelastic model was used to predict the post construction settlement distribution law of Yunnan Qiaojia high fill project, and the distribution area of maximum settlement rate and final settlement was proved, which provided a reasonable scientific basis for subsequent engineering measures. The compression modulus and viscosity coefficient of backfill materials of Yunnan Qiaojia high fill project retrieved based on viscoelastic constitutive model show significant spatial variability. If the spatial variability of parameters is not considered, significant errors will be generated in predicting post construction settlement. By meshing the monitoring areas, it can effectively improve the accuracy of prediction results to meet the engineering requirements.