Research conclusions:The design of the composite structure ofmini-pile shall follow the following points: Firstly, the space between piles can be considered as 2. 5-3. 5 times of the equivalentdiameter of themini-pile. Secondly, the landslide pushing force acting on the pile can be calculatedwith the landslide analysis calculationmethod. Thirdly, the calculationmode can be simplified as to calculate the multi-column frame with rigid top slab under the effects of pushing force or earth-pressure above the sliding surface, and for simplified calculation, the things below the sliding surfacemay be considered as the fixed end. Finally, the total shearing strength of the reinforced sliding-surface by mini-piles is equal to the sliding-surface itselfplus piles'shearing strength.