There is potential main landslip and thin-layer siliceous rock undisturbed at the lower part of the left side of Karst slop K133＋180. During the course of excavation, due to the effect of gravity, creep and ulcerate flexion slip surface might occur. From the slope geo-mechanics model perspective, this paper proposes two reinforce schemes on the slope based on the slope reinforce project experiences on the slope of similar condition in the area after taking into account the effect of rainfall conditions. The paper also compares the economic efficiency of the two schemes and considers that, provided that the slope design is stable, scheme 2 shall be more economically efficient. As a conclusion, the left slop K133＋180 was reinforced with scheme 2. So far, the slope keeps stable and firm through times of rainfall. The reinforce experience on the Karst slope K133+180 shall be able to act as a useful reference for similar projects.