Belt laser flowmeter uses 2D LiDAR to emit a laser line to the surface of the material, forming a contour line. This laser line contains many laser beams, and each laser beam reaches the material surface contour line to form multiple detection points. The material at each detection point generates a reflected beam, which is received by the photoelectric sensor inside the 2D LiDAR. By measuring the flight time of each laser beam from emission to reception, the distance between each detection point of the material surface contour line and the 2D LiDAR can be obtained and combined with the speed of the belt, the 3D dynamic view and the volume flow rate of the material transported on the belt can be measured, and the condition of the belt can also be known.