To get a deeper understanding of the relationship between the flat belt axial motion (FBAM) and the angles of rollers, a test rig was designed and some experiments were done. The belt axial position was measured though imaging processing. A special filtering procedure was proposed to eliminate the random and systematic errors. Base on the authors’ previous study, the normalized analytical FBAM model was given. By comparing the simulation and experimental results, the effectiveness of the analytical FBAM model was validated. The results also show the relationship between the FBAM and the belt transferring distance is independent of the belt transferring speed.