Abstract: After comprehensive assessing on seven static loading tests results of one failure piles engineering on mudstone subgrade in Nanning basin, the criterion, whose statistical value of axial single pile ultimate capacity adopts the average value after cancelling the peak value in turn until satisfy the condition that the relative difference between the peak value and minimum value won' t exceed 30 percent, is pointed that do not make enough use of piles potential bearing capacity.And it is a feasible way to treat the failure piles engineering problem by deformation control based on structural properties and loading and main factor of piles failure on the mudstone foundation is brought about by the decline of pile point capacity and pile side friction embedded in rock, which makes the piles bearing capacity deficient, which is also approved in the laboratory model test.Therefore, the success of boring pile will not only rely on adopting very low value of pile' s bearing capacity and pile side friction embedded in rock in piles foundation design.