Abstract：Based on Rumpf's mechanics analysis, the powder was considered as a random accumulation of homogeneous spherical particles. According to the logic axiomatic system requirements, the theoretical analysis of the stress was explored in an aspect of the powder layer under the action of a force.Consequently, the inherent regularity is revealed with the powders under the action of a force. The reasoning process is improved on the half-theory and half-experience stress analysis for powders. In order to further reveal the friction law and tensile strength of the powder layer, a good foundation has laid.

Keywords: powder layer; stress analysis; rigid model; spherical particle; uniformly distributed particle size; randomly packed bed