Abstract: In order to clarify the compression deformation rule of storage wheat grain bulk under long-term load and its impact on wheat quality, the compression deformation characteristics of wheat bulk under the condition of vertical pressure of 100-500 kPa were studied by uniaxial compression test, and the influence of compression deformation on wheat quality was studied with germination rate as the evaluation index. The results indicated that the compression deformation of wheat bulk mainly underwent three stages: instantaneous deformation, rapid deformation, and steady-state creep deformation. The instantaneous deformation of grain bulk in the stage of load increase was the main factor causing large compression deformation. The deformation and grain bulk density increased and the porosity decreased with the increase of vertical pressure. The creep model composed of Hooke spring and Kelvin model in series could better describe the compression deformation of wheat bulk. The curves in steady-state creep stage under different vertical pressures were parallel to each other. Compression deformation affected wheat kernels vigor, and with the increase of vertical pressure, germination rate decreased. The research results can provide theoretical support for grain storage safety management.