According to an exponential function describing the relation between friction around the pile and relative displacement of pile-soil，a constitutive model of interface is put forward and used as a means of studying pile-soil interaction with Goodman interface element。An elastically nonlinear constitutive model of concrete is employed to analyze stress-strain relationship of reinforced concrete under the axial load because of enough stress of reinforced concrete of the super-long pile。A compiled finite element program can solve layered soils and different characters of pile-soil interaction along the pile body caused by layered soils。According to the character of variational section of a case pile，it is considered as uniform section of pile with reasonable computing method assuring compute precision in the finite element program。Calculational results of the engineering case agree to statically loading testing results of the pile。