Abstract: In order to study the correlation changes in coal bunker material flow, based on the multidimensional discrete element method, the simulation study of coal bunker material flow in Haragou coal mine is carried out by adopting the particle flow correlation contact theory to investigate the influence law of coal particle size, coal stacking angle, and unloading hopper aperture on the material in the coal bunker. The study shows that: the change rule of the stress relaxation curve can be divided into a rapid rise stage, a slow decline stage and a stabilization stage, and the highest value of parameter A is 1.44 and 1.71 times that of parameter B and parameter C, respectively, and the corresponding values of the stabilization stage are 1.55 and 2.40 times, respectively. Unbonded theory is applicable to the description of the linear stage, and bonded theory is applicable to characterize the nonlinear features of the curve, and the nonlinear features of the coal bunker model can be analyzed and described by bonded theory. The output values corresponding to coal particle size, coal accumulation angle and unloading hopper caliber all show an overall trend of nearly linear change with the change of target value. The change curves of the force at different speeds show a rapid increase, followed by a slow decrease and finally tend to stabilize. When the speed increases slowly, the corresponding force decreases by about 5% and then by about 3.8%, indicating that the slower the speed is, the faster the corresponding force decreases. The simulation and application of simulation based on the multidimensional discrete element method in coal bunker flow can provide new theories and ideas for the study of coal materials.