[en] Due to the different fluidity greatly between U-M_o microsphere fuel particles and aluminum powders, segregation would take place during mixing and loading. In order to reduce segregation and improve the microcosmic uniformity of (U-M_o)-Al dispersion fuel seriously. The various coating process were carried out. The same size stainless steel microspheres were substituted for U-M_o microsphere particles in this paper. Results show that the adding directly binder process and the free falling process are not suitable for coating U-M_o microspheres. The solvent evaporation process can coat a layer of matrix powders on the surface of all U-M_o microsphere, which is feasible for microsphere physical coating. After coating, microsphere surface became uneven, the roughness increase greatly, and the bite force is exist between the particles during flowing, which reduce microsphere fluidity greatly. (authors)