In this paper, the operation of the vertical pendulum instrument at Shexian station in Handan City, Hubei Province, from 2011 to 2016 was analyzed, and the internal accuracy was calculated. The effects of load changes of surrounding project construction on the vertical pendulum were calculated by using the particle, two-dimensional, and three-dimensional load models. The results showed that the load change has no significant effect on the data of vertical pendulum at Shexian station. The results of two-dimensional and three-dimensional load models tend to be consistent. It is concluded that the inner accuracy of the vertical pendulum becomes bad during the period of ground breaking.