Research conclusions: The cause for the anti － slide pile fracture was the manual excavation and blasting when conducting the anti － slide pile to easily make some massifs in the deepest area where was the first to bore unstable and slide because the the places where the piles fractured were of the weak soft layers and their inclination of the fissure surfaces were basically with the that of the inclined slope of massif． Therefore，to avoid the anti － slide pile fracture in the construction，the small diameter (Φ= 20 cm) bore core would be used to form pore time and again and gradually form the rectangle pile pore，and at the same time the intervals anti － slide pile would be conducted． Namely，the second batch of the interval anti － slide pile would be conducted after 28 days that the concrete pouring to the first batch of the interval anti － slide pile was finished．