It is of great importance to guarantee the safety of slope and buildings when driving a horizontal chamber in the slope.In order toresearch slope stability while driving the horizontal chamber on this slope, the software FLAC3D was used to study the horizontal displacement of slope soil in different driving depth. The transverse settlements rules of the slope soil and the building foundation are analyzed numerically. And the numerical simulation results were compared with field monitoring. The results show that both the maximum transverse settlements position of the slope top and the building foundation were at the center line of the chamber. The horizontal displacement values were larger at the top andend but smaller in the middle. And it is beneficial for the slope stability and the buildings safety to enhance the supporting parameters of the entrance zone of the chamber. The results from the numerical simulation are consistent with the field monitoring, which can supply a reference for the similar engineering.