The erosion is a complex mechanical process in which material is removed from the pipeline due to repeated sand particle impacts. As a result, the pipeline can be eroded. Sand erosion is a threat to the flow assurance of subsea pipeline. Eroded pipelines may cause pipe failures which can result in financial losses and environmental issues. Taken a multiphase pipeline transporting oil, gas and water at Bohai sea as an example, the sand erosive wear depth is predicted year by year throughout the production period based on the impact damage model. The relation of annual sand erosion rate and total sand erosion depth is clarified, and the key factors affecting the rate of sand erosion are discussed. The results show that the control of the accumulative loss is closer to the actual situation of the project than that of the threshold speed, which provides a technical basis for the sand erosion allowance in engineering design.