In the automatic cutting process of casting pouring riser, the diameter of the grinding wheel is gradually reduced due to wear, which affects the positioning accuracy of the cutting process. Based on the laser distance meter, a method for automatic positioning by measuring the remaining diameter of the cutting blade after wear is proposed. ABAQUS finite element analysis software is used to design single-factor experiments to analyze the stress and temperature field before and after increasing the thickness of the cutting blade. The results of the study show that properly increasing the thickness of the cutting sheet is beneficial to avoid stress concentration and reduce the cutting temperature, and it is found that the surface morphology of the workpiece improved after the thickness of the cutting disc is increased.