Due to the complexity and uncertainty of the construction site, there is often a deviation between the actual excavation form of the slope and the designed excavation form. In order to avoid the potential safety hazards caused by the reduced stability of the slope due to the deviation, the slope excavation quality analysis and stability analysis were studied. A section of the high rock slope of Quanrong Expressway was taken as the research object. In view of the rock block sliding on the slope surface during the excavation process, the multi-view images of the slope were collected by unmanned aerial vehicle oblique photography, and the three-dimensional model of the slope was constructed by combining the three-dimensional reconstruction method. On this basis, the slope excavation quality analysis was carried out by the cross-section method, and the slope stability analysis was carried out by numerical simulation method. The analysis results show these as follows. There are two defects in the slope, which are manifested as local depression and local high slope rate. The overall stability of the slope meets the standard, but due to the existence of three groups of joints and fissures, gravel sliding may still occur near the slope surface. In order to prevent the slope rock from peeling off again, an active protection net system should be installed to reinforce the slope rock mass. It can be seen that the three-dimensional slope model reconstructed based on oblique photography can provide reliable spatial data support for excavation quality analysis and stability analysis at the same time. On this basis, it realizes the multi-dimensional analysis of the excavated slope and has strong practical application value.