The　hysteretic　recovering　force　of　soil　versus　its　displacement　reveals　a　symmetrical　hysteresis　under　a　horizontal　vibration＇s　compacting.　As　the　soil　compactness　is　high　enough,　slipping　appears　between　the　vibration　drum　of　a　road　roller　and　soil　supface.　Based　on　a　bilinear　symmetric　hysteresis　model,　a　piecewise　2-DOF　dynamic　model　of　the　road　roller　was　built　according　to　soil　property　parameters.　By　means　of　numerical　simulation,　the　influence　of　soil　parameters　and　horizontal　vibration　excitation　amplitude　&　frequency　on　the　response　of　the　vibratory　drum　were　analyzed.　Under　the　action　of　the　symmetrical　hysteretic　force,　the　super-harmonic　resonances　of　the　drum　occurred　and　their　spectra　revealed　the　fundamental　wave　plus　higher　odd　harmonics.　With　increase　in　soil　compactness,　even　and　fraction　harmonics　appeared　in　the　response　spectra　of　the　drum,　it　meaned　the　occurrence　of　slipping.　Under　a　certain　condition,　the　drum　entered　a　complex　quasi-periodic　motion.　Therefore,　adjusting　horizontal　vibration　excitation　amplitude　and　frequency　could　suppress　slipping,　and　make　the　drum　have　a　stable　double-periodic　motion