There are many deep excavations located in major cities because of the rapid development of underground engineering. The existence of deep excavations will affect the seismic response of the ground. However, there is great uncertainty concerning the dynamic performance of the adjacent ground and the current anti-earthquake design codes do not provide enough consideration to the problem. In this paper, a dynamic numerical simulation was performed to analyze the influence of deep excavations on the peak acceleration of the adjacent ground. In addition, the variation in peak acceleration along the depth was studied. The results show that the peak acceleration of the adjacent ground will significantly increase within a distance of two times the excavation depth.