The joint quality and fatigue life of rivets can be directly impacted by the verticality of holes at riveting parts in aircraft assembly. Then， it can further affect the mechanical properties of the aircraft. To improve the verticality of holes， factors influencing the normal accuracy of automatic drilling and riveting systems need to be analyzed. First， the relationship among the inclination error， the linear error of the mathematical model， and the normal error is determined. Then， the selection rules of the installation parameters of the laser displacement sensor are given， and the influences towards the pose calibration are studied. Finally， an experiment is designed to show real performance after optimizing the laser installation parameters. The research results can provide theoretical guidance for the design and analysis of the normal measuring device， and have a certain significance for improving the normal precision and the verticality of the hole in the automatic drilling and riveting system.