The affects of inclination of soil nails on the deformation and stability of excavation has been studied by designing and setting a laboratory model. A self-developed codes named 3D visualized monitoring system (3DVMS) has been adopted for comparing and verifying. The result indicated that the deformation and stability performance of excavation sidewall varies due to different inclination of soil nails. In conclusion

the soil nailing supports the sidewall best when the soil nails are inclined 30 degrees to the horizontal.