With the increasing demand for nickel ore in China, the import volume of nickel ore is increasing day by day. The fluidization of nickel ore in the process of marine transportation needs to be studied urgently. By means of indoor small vibration table modeling tests, the fluidization evolution process and the criterion for nickel ore's fluidization is studied. Firstly, with the aid of digital image acquisition and analysis system, the macro-evolution of nickel ore in fluidization process is analyzed, and the change rules of water content in layers and pore water pressure are studied. Based on the fluidization mechanism of nickel ore and the discrimination method for liquefaction of fine-grained soil, a new method for fluidization discrimination of nickel ore based on plasticity index is proposed. The results show that the fluidization of nickel ores is mainly caused by vibration softening under high water content conditions, during which water hardly migrates and pore water pressure hardly develops. The moisture content calculated by the discriminant method in this paper is basically consistent with the result of the model test. Therefore, the new method is suitable for determining the critical water content of fluidization of nickel ores with high fine particle content.