According to a new type of surround-pile-soil coupling anti-slide structure，based on the assumption of coupling of piles and soil，the coupling stiffness calculation formula is given，and the coupling stiffness change rule among pile number, pile spacing，pile diameter is analyzed. The result shows that stiffness increases with the increasing of pile spacing，pile diameter，pile number. To have a further discussion on the rationality of the arrangement，it is analyzed by using the equivalent radius and utilization degree of the coupling structure. The results show that using six piles，enclosing for 3 to 5 times the pile diameter，the pile spacing of plane model is more reasonable. The results of their research will provide a basis for the theory of the establishment of this new type of anti-slide structures.