Abstract: Slopes composed of overlying limestone and underlying thin weak shale are widely developed in Wuxi County, Northeast Chongqing. Such slopes are highly susceptible to sliding instability induced by rainfall with obvious delayed failure characteristics. Previous studies have primarily focus on the control effect of total rainfall on slope stability, while systematic analyses of slope deformation and prevention measures under different rainfall temporal patterns are insufficient. This study investigated Deformation Zone III of the Guang’an Village landslide in Wuxi to identify the disaster-inducing differences of various rainfall patterns and optimize targeted prevention and control measures. Based on multi-year measured rainfall statistical data, six typical rainfall temporal patterns including unimodal, front-peaked, rear-peaked, increasing, decreasing, and uniform typeswere classified using K-means clustering algorithm. A two-dimensional slope model was established via GEO-Studio to carry out numerical simulations of seepage field and slope stability under different rainfall patterns. Numerical simulations were also performed for three treatment schemes, namely independent interception-drainage system, single anti-slide piles, and the combined scheme of interception-drainage plus anti-slide piles, to compare the reinforcement performance and working mechanism of each measure. The results show that the total rainfall infiltration volume is the dominant controlling factor for the instability of slopes with the structural combination of shale weak base and fractured limestone. The disaster-induced effects of the six rainfall patterns are significantly different. Among them, the increasing rainfall pattern presents the most prominent failure effect and can directly trigger landslide instability; the unimodal rainfall pattern weakens slope stability to a certain extent; the slope remains stable under the action of front-peaked, rear-peaked, decreasing and uniform rainfall patterns. Under the condition of increasing rainfall, pore water pressure continuously accumulates along the potential sliding surface, forming a connected high pore water pressure zone at the landslide front. At the landslide rear, due to well-developed tensile fissures and favorable drainage conditions, the overall pore water pressure remains at a relatively low level. The combined scheme of interception-drainage and anti-slide piles achieves the optimal landslide prevention and control effect, limiting the stability attenuation range within 0.32%, significantly superior to single engineering measures. Rainfall temporal patterns dominate slope stability by regulating the accumulation process of pore water pressure. The integrated prevention and control mode combining source interception for seepage control and deep rigid anti-slide structures can markedly improve slope stability under sustained heavy rainfall, providing valuable guidance for early warning and engineering treatment of similar slope disasters.