PHC pipe pile in collapsible loess area has been widely used,for the characteristics of PHC pipe pile and the calculation of bearing capacity in the collapsible loess,introduce the concept of friction neutral point.With a complete design and calculation is based on the engineering example of data and field test,the design of PHC pipe pile in collapsible loess foundation calculation and test carried on detailed analysis,research and discussion,and will be the basic form and the other basic is used for economical comparison.