Abstract: In order to study the influence of excavation and house building on slope stablity, this paper analyzes the distribution and disaster models of geological disasters in the area of Luniao Town, Yuhang District, Zhejiang Province, and generalizes four types of slope models. The finite element limit equilibrium method is used to simulate the variation of stress, strain distribution and safety factor after the slope excavation, and then the threshold value of the excavation footage at the time of instability can be obtained through fitting the relationship between slope excavation footage and slope safety factor by the function curve. The result shows that:(1) Under natural conditiond the potential instability zone of the slope is located at the slope crest, and the probability of instability near the slope is higher than the other part of the slope. (2) When the slope is excavated, the slope and the excavation footage will jointly affect the slope stability, and the effect of the slope is greater than the excavation footage. (3) The error analysis shows that the threshold error of the slope with slope less than 20° is larger, and the threshold error of the slope with slope greater than 20° is smaller.