Objective In order to study the properties and application effect of micro-nano potato starch fat mimics.Methods The enzymatic hydrolysis potato starch fat mimics was treated by dynamic ultra-high pressure micro-jet technology, and it was applied to replace fat in chiffon cake.Results The results showed that the particle size of fat simulant particles decreased from 3 550.33 nm to 532.40 nm, the solubility increased from 84.24% to 92.22%, and the branching degree decreased from 14.57% to 12.84% after the treatment of dynamic ultra-high pressure micro-jet technology.After dynamic ultra-high pressure micro-jet treatment, the micro-nano potato starch fat mimics did not form new functional groups, but the peak intensity of infrared spectrum changed, the fluorescence intensity decreased, the pyrolysis rate decreased, and the thermal stability of the system increased.Conclusion The specific volume, sensory quality and texture characteristics of chiffon cake made from micro-nano potato starch fat simulant are better than those made by enzymatic hydrolysis fat simulant, and the fat replacement rate is increased by 10%.