In-situ monitoring experiment was carried out in combination with the slope of the Lixian-Xiaojin Highway in Sichuan Province seismic area. In the period of monitoring, three earthquakes whose magnitudes were more than 4.8 grades occurred in this area. Based on the monitoring results, the main conclusions are as followed. The deformation of overall of the surface rock structure has a process of rapid increase, which indicates that the construction still produces the largest effect on the loose deformation of rock slope in this seismic area. For reverse structural surface, the rock structure of slope surface would also produce compacted deformation by earthquake, which was conducive to the stability of rock slope.