Based on consolidation compression, creep and tri-axial tests on undisturbed loess, the paper studies its deformation and strength characteristics at high pressure and mainly draws the following conclusions: reduction of load increment or increase of moisture content may improve the compressibility of soil; creep deformation of undisturbed loess has a constant-speed growth trend at high pressure; a stress-strain-time formula in the exponential function form is put forward; the stress-strain relationships of saturated loess and unsaturated loess at high pressure are respectively softening and hardening, and along with increase of confining pressure, the softening or hardening degree is increasing; and the strength of undisturbed loess at high confining pressure shows obvious non-linearity; the breakage mechanism of undisturbed loess at high confining pressure is analyzed under the frame of breakage mechanics for geological materials.