Abstract: A  new  mechanical  model    the  dynamic  finite  layer  element  model  is  proposed  to  analyze  the  dynamic  nonlinear  respose  for  pile-soil  interaction  based  on  the  finite  layer  and  finite  element  methods      The corresponding theoretical formula is derived  The spatial problem of semi  infinite body is transformed to a pseudo  two  dimensional problem and solved  It is shown by the   results  of  some  example  that  this  method  is  convenient  and  reliable,  and  can  be  applied  widely  in  the  engineering  practice