Loess,　with　penetrability,　collapsibility,　slaking,　is　uniform　in　grain　and　high　in　porosity　and　low　in　moisture　content.　In　the　northwest　China,　geological　calamities,　such　as　soil　erosion,　slope　slide,　debris　flow　and　landslip,　etc,　frequently　occur　in　the　loess　area　in　the　condition　of　large　rainfall,　which　may　brings　tremendous　loss　and　damage　to　highway.　Geosynthetics　is　an　effective　method　to　the　solution　of　these　problems.　The　construction　process　of　loess　reinforcement　embankment　is　modeled　using　FLAC.　Based　on　uniaxial　compression　test　and　dynamic　modulus　input　technique　with　programmable　FISH,　the　compact　quality　of　loess　can　well　be　depicted.　A　reinforcing　expressway　embankment　in　Ningxia　is　modeled　using　this　method,　and　the　results　are　close　to　the　field　data.　At　the　same　time,　the　internal　force　distribution　in　geogrid　is　analyzed,　and　reinforcing　effect　is　appraised.　These　results　may　help　promote　the　application　of　geosynthetics　in　loess　embankment.