In　order　to　study　the　creep　property　of　salt　rock,　triaxial　compression　creep　tests　with　step　loading　axial　stress　to　salt　rock　specimens　were　carried　out　on　the　RLW-2000　rock　rheology　testing　machine.　The　test　results　show　that　the　instantaneous　strain,　creep　strain　and　creep　velocity　of　salt　rock　increase　gradually　with　the　increasing　of　axial　stress,　meanwhile,　the　duration　of　the　primary　creep　stage　gradually　extend.　And　isochronous　stress-strain　curves　of　salt　rock　indicate　that　the　creep　process　of　salt　rock　has　nonlinear　characteristic,　and　the　nonlinear　degree　is　related　to　creep　time　and　stress　level.　Based　on　nonlinear　rheological　theory,　a　new　nonlinear　viscosity　component　with　a　variable　viscosity　coefficient　was　proposed,　and　the　viscosity　coefficient　of　which　was　time　and　stress-dependent.　Then,　by　using　this　proposed　nonlinear　component　to　replace　the　conventional　viscous　components　in　Burgers　model,　a　nonlinear　viscoelasticity　creep　model,　which　was　named　MBurgers　model　and　can　describe　the　nonlinear　creep　property　of　salt　rock　was　established.　According　to　triaxial　compression　creep　test　results　of　salt　rock,　the　parameters　of　MBurgers　model　were　inversed　by　using　curve　fitting　method.　And　the　theoretical　curves　accord　well　with　the　test　curves,　which　indicates　that　the　MBurgers　model　can　describe　the　creep　property　of　salt　rock.