Aiming at the problems such as low efficiency and inaccurate results in powder pile inventory, a quality measurement method based on modified cam clay model is studied, the feasibility of this method is verified by the quality measurement experiment of small quartz sand. In order to improve the efficiency of material quality inventory and the accuracy of measurement results, a stress-density model is constructed based on the integral principle and the stress-strain relationship described by the modified cam clay model, based on the thin-film pressure sensor, a density measuring device is designed, and two different kinds of stacking materials are designed according to the common stacking materials in the storage yard, the density can be obtained by the pressure at different height and radial depth, and the volume can be obtained by the point cloud data of three-dimensional laser scanner. The experimental results show that the relative error of the results obtained by this method is below 4% for quartz sand piles with masses of 92.1 kg and 86.1 kg. The experimental results prove the feasibility of the measurement method, which can provide reference for the inventory of large-scale stack and help enterprises to make further production planning.