Abstract: Abstract: In the process of animal feed processing, a large number of powder materials are involved in the process. From the grinding of raw materials to the stock bin, the feeding equipment connecting each process, and the mixing machine, materials are all at the powder state. In the transportation and storage process of powder materials, due to the interaction between particles, problems such as knot arch, rat hole, low flow rate, even blockage will arise. To solve the above problems, it is necessary to explore the flow characteristics of different powders. Select two raw materials that account for a large proportion in the feed formula of livestock and poultry: Soybean meal and corn DDGS. Using respectively equipped with 1.5, 2.0 and 2.5 mm sieve aperture crusher for crushing, obtain the granular powder raw material, the moisture content of raw materials after crushed is about 10%, and after mixing machine, the moisture content is about 14%, so this study powder moisture content (wet basis) gradient is set to 10%, 12% and 14%, respectively. By drying and adding water, obtaining corresponding moisture content of the powder materials. The stress of materials in silos increases with the increase of the height, the consolidation stress range was set as 1-3 kPa based on the stress level of the powder in actual production. This paper chooses three kinds of crushing granularity (shattered screen surface pore size: 1.5, 2.0 and 2.5 mm) of soybean meal and corn DDGS as the research object. Based on the measured shear method of powder flow meter in different moisture content (10% ~ 14%, wet basis) and different consolidation stress(1-3 kPa), explore the characterization of the change of its flowability, and analyzes the three factors on the influence law of liquidity, and build the prediction model of cohesion of research variables. The results showed that the flowability of soybean meal and DDGS powder was significantly affected by consolidation stress, moisture content and particle size, and was also affected by the interaction of the three factors. Consolidation stress was the most significant, moisture content and crushing particle size were the second. With the increase of consolidation stress, the spacing between the particles of soybean meal powder decreased due to compression, which led to the increase of van der Waals force and impeded the movement between the two particles, and thus the flowability of the powder became worse. As the mesh size decreased, the particle size decreased, resulting in more compact powder accumulation, which showed a law of poor flowability. As the moisture content of powder increased, the capillary force between particles increased, thereby increasing the adhesion between particles, thus reducing the flowability of the powder. DDGS powder showed a similar rule. A multiple regression model (R2>0.957) of cohesion on moisture content, consolidation stress and particle size was established based on the experimental data, which could effectively predict the flow characteristics of powder of the two feed materials in the paper. The results provided the theoretical basis for the storage, transportation and mixing process parameters optimization of feed materials powder of raw materials.