Abstract: The decrease in the bearing capacity of a single pile and the additional deformation will occur when the shield machine approaches the existing pile. Effects of shield tunneling on a single existing pile are investigated by means of the numerical method in this study in the case of shield machine passing laterally. Earth pressures in the chamber of the shield machine and change in the distance between the pile and the shield machine are taken into account in the numerical simulation. It shows the two factors, i.e., earth pressures in the chamber and the distance, play an important role in this process. Moments along the pile and settlements at the top of the pile are obtained as well. It is proved that the decrease in the bearing capacity of the pile and the increase in the settlement are significant during the shield tunneling. Therefore, some measures should be taken to protect the existing pile from damage. Moreover, the earth pressures in the chamber can prevent effectively the pile from decreasing in the bearing capacity, and to some extent, it can control the settlement induced by the shield tunneling.