A number of crude oils is transported by Tangyan crude oil pipeline with frequent switch and thus wax deposition prediction is difficult. In this paper, wax deposition rates of different transported crudes along Tangyan pipeline in different seasons are predicted by using the unified wax deposition model based on crude properties. The thickness and distribution of wax deposition are forecasted, which provide a theoretical basis for the pigging operation securely. The results show that the wax deposition rates of different crudes in different seasons are various. Wax deposition along Tangyan pipeline mostly happens in winter and seldom happens in summer. Wax deposition of Aisipo and Maxila crude oil is less than that of Jienuo and Shazhong crude oil. The distribution of wax deposition along the pipelineis uneven. Wax deposition mainly accumulates in the inlets of the pump stations. When there is little variation of pipeline operation stress, the pressure drop in the unit length increases rapidly in the position where wax deposition is serious. Pressure effect may cause potential security risks in the pipeline. It is suggested that the pigging operation should be conducted in each autumn.