In this paper, the particle dynamics and free surface in a simplified disc device are studied using experiments and the Discrete Element Method (DEM). Two different kinds of free surface formula for the motion of particles in a disc device are derived and calculated. The disc rotational speed, particle filling rate, and particle materials are used as three experimental control parameters, and the experimental results are compared with the numerical calculation results. In order to obtain the dynamic distribution of particles, the influence of contact friction parameters are discussed by the DEM simulation. Besides the operating conditions, it can be observed that the particle material properties play an important role in particle dynamic distribution and DEM granular flow prediction. The results prove a feasible prediction of the particle free surface physical models, which also provides a method and theoretical basis to predict the particle flow characteristics in the vertical screw conveying.