Quantifying the geometric structure of packing particles is of great value for understanding the macroscopic mechanical properties of particle systems. In this paper, Cell was utilized to measure the geometric structure of disk particles in a two-dimensional silo. The probability distribution of Cell shapes satisfied the exponential function distribution and was independent of the system size. Furthermore, it was observed that under the condition of vibration driving, the triangular-shaped Cell had a surge, and the formation probability increased by 19%, while the probability distribution of the rest shapes of Cell still satisfied the exponential function distribution. The experimental results reveal the structural characteristics of ordered packing in disordered particle system at intermediate scale, and provide references for perfecting the theory of particle mechanics.