The invention discloses a method of determining the position range of compression states in dredging system of a two-phase flow submersible pump, which is suitable for dredging rivers and lakes and for long-distance sand transportation. The spacing range between the dredging platform and the compression stations is determined according to the selected pipeline materials and the performance parameters of the compression station pumps and the submersible pumps on the dredging platform after calculating the hydraulic gradient of the mud pipelines of the dredging system for transporting mud with the established mathematical model. The method with significant economic benefits has changed the method of determining the position of compression states based on the construction experience or construction practice, which optimizes the dredging system operation, improves the system safety and efficiency, and saves energy consumption for sand transporation.