In order to solve the safety problems caused by the villagers’ self-excavation of slopes in rural Chongqing Tongliang, this paper obtains the characteristics of the slopes behind the houses in rural Chongqing Tongliang and numerically simulates the characteristic slopes through field investigation and Flac3D software. At the same time, the gray correlation method is used to analyze the influence of each variable on the slope stability factor. The results show that: (1) Most of the slopes behind rural houses in Chongqing Tongliang have a slope height of 4–6 m, a slope angle of 50°–100°, and most of them are rocky or rock-soil composite slopes, and 63.5% of the slopes do not have any support measures. (2) When the slope angle is certain, the slope stability factor decreases gradually with the increase of slope height, and the rate of decrease slows down gradually; when the slope height is certain, the change curve of the slope stability factor with the slope angle can be regarded as a linear function, and the stability factor decreases with the increase of slope angle. (3) The correlation between slope angle and stability factor is the strongest; with the increase of slope height, the negative effect of slope height on stability factor decreases gradually. (4) The stability suggestions of Tongliang rural slope excavation in Chongqing can provide a reference basis for subsequent rural slope excavation.