An experimental device for high water⁃cut crude oil is designed and built, which mainly includes test pipeline, oil⁃water separation system, data acquisition system and circuit control system. The test section is designed of organic glass tube with a water bath, which observes flow morphology and initial deposition process. Considering the working conditions in the production site, oil⁃water mixing device is designed by drawing lesson of the principle of jet mixer. In order to ensure the effective separation of free water and crude oil during the experiment, an oil⁃water separator suitable for high water⁃cut crude oil is designed on the basis of free water separator. At the same time, a data acquisition system and circuit control system are designed, which can effectively solve the problems of data acquisition and parameter control. After Experimental verification, the experimental device can fulfill the research work of flow and deposition of high water⁃cut crude oil.