Based on a macro analysis of the engineering survey of the south slope of Waimao road, a quantitative calculation has thus been made of the local and overall stability of the south side slope of Waimao road by using the circular arc sliding slice method in the limit equilibrium theory. The calculated parameters are evaluated by geological survey results, while the stability coefficient Fs of the landslide is calculated by using the circular arc sliding slice method. The calculation results show that the local stability of the slope is in a stable state under normal working conditions, while in an unstable state under the condition of rainstorm, the overall stability of the slope is checked, whereas it is stable under normal and rainstorm conditions; based on the results of stability analysis, an analysis has been made of the causes of slope instability, followed by some measures put forward for the treatment of crack grouting at the top of slope, dynamic compaction of loose soil on the slope, as well as retaining wall at the toe of slope.