In order to improve the nutritional value of metric staple food， rice flour and potato snowflake whole powder were mixed according to different proportions. The microstructure， chemical structure， crystal structure， particle size， gelatinization property， thermal stability and rheological properties of the powder were analyzed and studied by means of scanning electron microscope， infrared spectrometer， X-ray diffractometer， particle size analyzer， viscometer， differential thermal analyzer， rheometer and texture analyzer. The results showed that the surface of rice flour and potato snowflake powder was smoother than that of potato flour. The surface of potato flour was damaged in the process of production， so the surface of rice flour looked irregular and rough. The infrared spectral peak position of different proportions of mixed powder was basically the same， and the structure of functional groups did not change significantly. The crystal structure of rice flour and potato flour both belong to A-type crystal， and the crystallinity of mixed flour increases with the increase of the proportion of potato flour. The average particle size of rice flour was 82.35 μm， and that of potato whole meal was 280.8 μm. With the increase of the proportion of potato whole meal， the average particle size of mixed meal increased. With the increase of the total flour proportion， the gelatinization temperature and gelatinization enthalpy， the energy storage modulus and energy dissipation modulus， the solubility and swelling degree， the resilience， cohesion， viscosity， decay value and recovery value， the hardness， elasticity and chewability of the potato decreased， and the freeze-thaw stability decreased. The mixing ratio of rice flour and potato flour has a significant effect on the grain structure and physicochemical properties of the mixed flour， which provides reference data for the development of mixed rice staple food.