The experiment studied granularity distributed from 1.3-3.0mm in the vibration loading process of molecular sieve, and the influence of all kinds of vibration parameters such as vibration frequency, vibration amplitude on the molecular sieve packing density. The effects of operational conditions on packing density have been analyzed. The results show that the packing density firstly increases with the increasing frequency to a peak value and then reduces, and the frequency has a best value. It is mean that there exist optimum values for A and f to achieve the maximum packing density. And the relationship between amplitude and packing density is the same as the effect of the frequency on packing density. These could serve as the basis in determining the technological parameters of the vibration loading progress of the molecular sieve at this particle size scale.