Belt conveyors are efficient devices that transport materials using friction and are widely used in industries such as coal transportation, metal processing, and grain storage. Measuring the material flow on conveyor belts is a critical step in the production process. Traditional methods use belt scales for weighing, which involve complex installation, high maintenance costs, and expensive equipment. This paper proposes a non-contact method for measuring material flow on belt conveyors using LiDAR. After acquiring point clouds with LiDAR, we first remove motion distortion, then filter out the conveyor belt points based on the Euclidean distance of the micro-element geometric center. The volume of micro-element slices is calculated using both the triangular mesh method and the voxel filling method. Finally, the material flow is computed through micro-element integration. The feasibility of the algorithm is verified by scanning regular objects to calculate their volume, and the accuracy and stability of the triangular mesh method and the voxel filling method are compared. Experimental results show that the average relative error percentage of the triangular mesh method is 2.685%, while that of the voxel filling method is 1.135%. The variance of measurements for both methods is [Formula: see text], indicating high computational stability. The measurement accuracy level has improved by 1%–2% compared with existing work.