Abstract: To simulate the uniaxial powder compacting process, the 3D particle accumulation is generated using 3D discrete element method technology and the experimental grading ratio. During the powder compacting process, the evolution law and topological properties of the force chains are investigated. The jamming phenomenon is further investigated using the velocity and coordination number of particles, and the correlation mechanism between the force chain and the jamming behavior is discussed. The results show that as the compression strength of the upper die gradually increases from 0 to 60 MPa, the proportion of force chain particles rapidly increases to more than 40%, while the proportion of high stress particles is stable above 12.5%. When the pressure exceeds 60 MPa, the force chains bend and form ring structure, causing the jamming phenomenon. As a result, the jammed point is set to 60 MPa. The jamming phenomenon also effects the powder densification. The axial velocity of the powder particles in the upper area is faster and the rangeability is larger than that of the powder particles in the lower area during the powder compaction process. However, when the compaction process is completed, the densification degree of the powder particles in the upper area is higher than that of the powder particles in the lower area.